src/lib/radius.c

   1 /*
   2  * radius.c     Functions to send/receive radius packets.
   3  *
   4  * Version:     $Id$
   5  *
   6  *   This library is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU Lesser General Public
   8  *   License as published by the Free Software Foundation; either
   9  *   version 2.1 of the License, or (at your option) any later version.
  10  *
  11  *   This library is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14  *   Lesser General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Lesser General Public
  17  *   License along with this library; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2000-2003,2006  The FreeRADIUS server project
  21  */
  22
  23 #include        <freeradius-devel/ident.h>
  24 RCSID("$Id$")
  25
  26 #include        <freeradius-devel/libradius.h>
  27 #include        <freeradius-devel/md5.h>
  28
  29 #include        <fcntl.h>
  30 #include        <ctype.h>
  31
  32 #ifdef WITH_UDPFROMTO
  33 #include        <freeradius-devel/udpfromto.h>
  34 #endif
  35
  36 #ifdef HAVE_MALLOC_H
  37 #include        <malloc.h>
  38 #endif
  39
  40 /*
  41  *  The RFC says 4096 octets max, and most packets are less than 256.
  42  */
  43 #define MAX_PACKET_LEN 4096
  44
  45 /*
  46  *      The maximum number of attributes which we allow in an incoming
  47  *      request.  If there are more attributes than this, the request
  48  *      is rejected.
  49  *
  50  *      This helps to minimize the potential for a DoS, when an
  51  *      attacker spoofs Access-Request packets, which don't have a
  52  *      Message-Authenticator attribute.  This means that the packet
  53  *      is unsigned, and the attacker can use resources on the server,
  54  *      even if the end request is rejected.
  55  */
  56 int fr_max_attributes = 0;
  57 FILE *fr_log_fp = NULL;
  58
  59 typedef struct radius_packet_t {
  60   uint8_t       code;
  61   uint8_t       id;
  62   uint8_t       length[2];
  63   uint8_t       vector[AUTH_VECTOR_LEN];
  64   uint8_t       data[1];
  65 } radius_packet_t;
  66
  67 static fr_randctx fr_rand_pool; /* across multiple calls */
  68 static int fr_rand_initialized = 0;
  69 static unsigned int salt_offset = 0;
  70
  71 const char *fr_packet_codes[FR_MAX_PACKET_CODE] = {
  72   "",
  73   "Access-Request",
  74   "Access-Accept",
  75   "Access-Reject",
  76   "Accounting-Request",
  77   "Accounting-Response",
  78   "Accounting-Status",
  79   "Password-Request",
  80   "Password-Accept",
  81   "Password-Reject",
  82   "Accounting-Message",
  83   "Access-Challenge",
  84   "Status-Server",
  85   "Status-Client",
  86   "14",
  87   "15",
  88   "16",
  89   "17",
  90   "18",
  91   "19",
  92   "20",
  93   "Resource-Free-Request",
  94   "Resource-Free-Response",
  95   "Resource-Query-Request",
  96   "Resource-Query-Response",
  97   "Alternate-Resource-Reclaim-Request",
  98   "NAS-Reboot-Request",
  99   "NAS-Reboot-Response",
 100   "28",
 101   "Next-Passcode",
 102   "New-Pin",
 103   "Terminate-Session",
 104   "Password-Expired",
 105   "Event-Request",
 106   "Event-Response",
 107   "35",
 108   "36",
 109   "37",
 110   "38",
 111   "39",
 112   "Disconnect-Request",
 113   "Disconnect-ACK",
 114   "Disconnect-NAK",
 115   "CoA-Request",
 116   "CoA-ACK",
 117   "CoA-NAK",
 118   "46",
 119   "47",
 120   "48",
 121   "49",
 122   "IP-Address-Allocate",
 123   "IP-Address-Release"
 124 };
 125
 126
 127 void fr_printf_log(const char *fmt, ...)
 128 {
 129         va_list ap;
 130
 131         va_start(ap, fmt);
 132         if ((fr_debug_flag == 0) || !fr_log_fp) {
 133                 va_end(ap);
 134                 return;
 135         }
 136
 137         vfprintf(fr_log_fp, fmt, ap);
 138         va_end(ap);
 139
 140         return;
 141 }
 142
 143 static void print_hex(RADIUS_PACKET *packet)
 144 {
 145         int i;
 146
 147         if (!packet->data) return;
 148
 149         printf("  Code:\t\t%u\n", packet->data[0]);
 150         printf("  Id:\t\t%u\n", packet->data[1]);
 151         printf("  Length:\t%u\n", ((packet->data[2] << 8) |
 152                                    (packet->data[3])));
 153         printf("  Vector:\t");
 154         for (i = 4; i < 20; i++) {
 155                 printf("%02x", packet->data[i]);
 156         }
 157         printf("\n");
 158
 159         if (packet->data_len > 20) {
 160                 int total;
 161                 const uint8_t *ptr;
 162                 printf("  Data:");
 163
 164                 total = packet->data_len - 20;
 165                 ptr = packet->data + 20;
 166
 167                 while (total > 0) {
 168                         int attrlen;
 169
 170                         printf("\t\t");
 171                         if (total < 2) { /* too short */
 172                                 printf("%02x\n", *ptr);
 173                                 break;
 174                         }
 175
 176                         if (ptr[1] > total) { /* too long */
 177                                 for (i = 0; i < total; i++) {
 178                                         printf("%02x ", ptr[i]);
 179                                 }
 180                                 break;
 181                         }
 182
 183                         printf("%02x  %02x  ", ptr[0], ptr[1]);
 184                         attrlen = ptr[1] - 2;
 185                         ptr += 2;
 186                         total -= 2;
 187
 188                         for (i = 0; i < attrlen; i++) {
 189                                 if ((i > 0) && ((i & 0x0f) == 0x00))
 190                                         printf("\t\t\t");
 191                                 printf("%02x ", ptr[i]);
 192                                 if ((i & 0x0f) == 0x0f) printf("\n");
 193                         }
 194
 195                         if ((attrlen & 0x0f) != 0x00) printf("\n");
 196
 197                         ptr += attrlen;
 198                         total -= attrlen;
 199                 }
 200         }
 201         fflush(stdout);
 202 }
 203
 204
 205 /*
 206  *      Wrapper for sendto which handles sendfromto, IPv6, and all
 207  *      possible combinations.
 208  */
 209 static int rad_sendto(int sockfd, void *data, size_t data_len, int flags,
 210                       fr_ipaddr_t *src_ipaddr, int src_port,
 211                       fr_ipaddr_t *dst_ipaddr, int dst_port)
 212 {
 213         struct sockaddr_storage dst;
 214         socklen_t               sizeof_dst;
 215
 216 #ifdef WITH_UDPFROMTO
 217         struct sockaddr_storage src;
 218         socklen_t               sizeof_src;
 219
 220         fr_ipaddr2sockaddr(src_ipaddr, src_port, &src, &sizeof_src);
 221 #else
 222         src_port = src_port;    /* -Wunused */
 223 #endif
 224
 225         if (!fr_ipaddr2sockaddr(dst_ipaddr, dst_port, &dst, &sizeof_dst)) {
 226                 return -1;
 227         }
 228
 229 #ifdef WITH_UDPFROMTO
 230         /*
 231          *      Only IPv4 is supported for udpfromto.
 232          *
 233          *      And if they don't specify a source IP address, don't
 234          *      use udpfromto.
 235          */
 236         if ((dst_ipaddr->af == AF_INET) ||
 237             (src_ipaddr->af != AF_UNSPEC)) {
 238                 return sendfromto(sockfd, data, data_len, flags,
 239                                   (struct sockaddr *)&src, sizeof_src,
 240                                   (struct sockaddr *)&dst, sizeof_dst);
 241         }
 242 #else
 243         src_ipaddr = src_ipaddr; /* -Wunused */
 244 #endif
 245
 246         /*
 247          *      No udpfromto, OR an IPv6 socket, fail gracefully.
 248          */
 249         return sendto(sockfd, data, data_len, flags,
 250                       (struct sockaddr *) &dst, sizeof_dst);
 251 }
 252
 253
 254 void rad_recv_discard(int sockfd)
 255 {
 256         uint8_t                 header[4];
 257         struct sockaddr_storage src;
 258         socklen_t               sizeof_src = sizeof(src);
 259
 260         recvfrom(sockfd, header, sizeof(header), 0,
 261                  (struct sockaddr *)&src, &sizeof_src);
 262 }
 263
 264
 265 ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, int *src_port,
 266                         int *code)
 267 {
 268         ssize_t                 data_len, packet_len;
 269         uint8_t                 header[4];
 270         struct sockaddr_storage src;
 271         socklen_t               sizeof_src = sizeof(src);
 272
 273         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 274                             (struct sockaddr *)&src, &sizeof_src);
 275         if (data_len < 0) {
 276                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 277                 return -1;
 278         }
 279
 280         /*
 281          *      Too little data is available, discard the packet.
 282          */
 283         if (data_len < 4) {
 284                 recvfrom(sockfd, header, sizeof(header), 0,
 285                          (struct sockaddr *)&src, &sizeof_src);
 286                 return 1;
 287
 288         } else {                /* we got 4 bytes of data. */
 289                 /*
 290                  *      See how long the packet says it is.
 291                  */
 292                 packet_len = (header[2] * 256) + header[3];
 293
 294                 /*
 295                  *      The length in the packet says it's less than
 296                  *      a RADIUS header length: discard it.
 297                  */
 298                 if (packet_len < AUTH_HDR_LEN) {
 299                         recvfrom(sockfd, header, sizeof(header), 0,
 300                                  (struct sockaddr *)&src, &sizeof_src);
 301                         return 1;
 302
 303                         /*
 304                          *      Enforce RFC requirements, for sanity.
 305                          *      Anything after 4k will be discarded.
 306                          */
 307                 } else if (packet_len > MAX_PACKET_LEN) {
 308                         recvfrom(sockfd, header, sizeof(header), 0,
 309                                  (struct sockaddr *)&src, &sizeof_src);
 310                         return 1;
 311                 }
 312         }
 313
 314         /*
 315          *      Convert AF.  If unknown, discard packet.
 316          */
 317         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, src_port)) {
 318                 recvfrom(sockfd, header, sizeof(header), 0,
 319                          (struct sockaddr *)&src, &sizeof_src);
 320                 return 1;
 321         }
 322
 323         *code = header[0];
 324
 325         /*
 326          *      The packet says it's this long, but the actual UDP
 327          *      size could still be smaller.
 328          */
 329         return packet_len;
 330 }
 331
 332
 333 /*
 334  *      wrapper for recvfrom, which handles recvfromto, IPv6, and all
 335  *      possible combinations.
 336  */
 337 static ssize_t rad_recvfrom(int sockfd, uint8_t **pbuf, int flags,
 338                             fr_ipaddr_t *src_ipaddr, uint16_t *src_port,
 339                             fr_ipaddr_t *dst_ipaddr, uint16_t *dst_port)
 340 {
 341         struct sockaddr_storage src;
 342         struct sockaddr_storage dst;
 343         socklen_t               sizeof_src = sizeof(src);
 344         socklen_t               sizeof_dst = sizeof(dst);
 345         ssize_t                 data_len;
 346         uint8_t                 header[4];
 347         void                    *buf;
 348         size_t                  len;
 349         int                     port;
 350
 351         memset(&src, 0, sizeof_src);
 352         memset(&dst, 0, sizeof_dst);
 353
 354         /*
 355          *      Get address family, etc. first, so we know if we
 356          *      need to do udpfromto.
 357          *
 358          *      FIXME: udpfromto also does this, but it's not
 359          *      a critical problem.
 360          */
 361         if (getsockname(sockfd, (struct sockaddr *)&dst,
 362                         &sizeof_dst) < 0) return -1;
 363
 364         /*
 365          *      Read the length of the packet, from the packet.
 366          *      This lets us allocate the buffer to use for
 367          *      reading the rest of the packet.
 368          */
 369         data_len = recvfrom(sockfd, header, sizeof(header), MSG_PEEK,
 370                             (struct sockaddr *)&src, &sizeof_src);
 371         if (data_len < 0) {
 372                 if ((errno == EAGAIN) || (errno == EINTR)) return 0;
 373                 return -1;
 374         }
 375
 376         /*
 377          *      Too little data is available, discard the packet.
 378          */
 379         if (data_len < 4) {
 380                 recvfrom(sockfd, header, sizeof(header), flags,
 381                          (struct sockaddr *)&src, &sizeof_src);
 382                 return 0;
 383
 384         } else {                /* we got 4 bytes of data. */
 385                 /*
 386                  *      See how long the packet says it is.
 387                  */
 388                 len = (header[2] * 256) + header[3];
 389
 390                 /*
 391                  *      The length in the packet says it's less than
 392                  *      a RADIUS header length: discard it.
 393                  */
 394                 if (len < AUTH_HDR_LEN) {
 395                         recvfrom(sockfd, header, sizeof(header), flags,
 396                                  (struct sockaddr *)&src, &sizeof_src);
 397                         return 0;
 398
 399                         /*
 400                          *      Enforce RFC requirements, for sanity.
 401                          *      Anything after 4k will be discarded.
 402                          */
 403                 } else if (len > MAX_PACKET_LEN) {
 404                         recvfrom(sockfd, header, sizeof(header), flags,
 405                                  (struct sockaddr *)&src, &sizeof_src);
 406                         return len;
 407                 }
 408         }
 409
 410         buf = malloc(len);
 411         if (!buf) return -1;
 412
 413         /*
 414          *      Receive the packet.  The OS will discard any data in the
 415          *      packet after "len" bytes.
 416          */
 417 #ifdef WITH_UDPFROMTO
 418         if (dst.ss_family == AF_INET) {
 419                 data_len = recvfromto(sockfd, buf, len, flags,
 420                                       (struct sockaddr *)&src, &sizeof_src,
 421                                       (struct sockaddr *)&dst, &sizeof_dst);
 422         } else
 423 #endif
 424                 /*
 425                  *      No udpfromto, OR an IPv6 socket.  Fail gracefully.
 426                  */
 427                 data_len = recvfrom(sockfd, buf, len, flags,
 428                                     (struct sockaddr *)&src, &sizeof_src);
 429         if (data_len < 0) {
 430                 free(buf);
 431                 return data_len;
 432         }
 433
 434         if (!fr_sockaddr2ipaddr(&src, sizeof_src, src_ipaddr, &port)) {
 435                 free(buf);
 436                 return -1;      /* Unknown address family, Die Die Die! */
 437         }
 438         *src_port = port;
 439
 440         fr_sockaddr2ipaddr(&dst, sizeof_dst, dst_ipaddr, &port);
 441         *dst_port = port;
 442
 443         /*
 444          *      Different address families should never happen.
 445          */
 446         if (src.ss_family != dst.ss_family) {
 447                 free(buf);
 448                 return -1;
 449         }
 450
 451         /*
 452          *      Tell the caller about the data
 453          */
 454         *pbuf = buf;
 455
 456         return data_len;
 457 }
 458
 459
 460 #define AUTH_PASS_LEN (AUTH_VECTOR_LEN)
 461 /*************************************************************************
 462  *
 463  *      Function: make_secret
 464  *
 465  *      Purpose: Build an encrypted secret value to return in a reply
 466  *               packet.  The secret is hidden by xoring with a MD5 digest
 467  *               created from the shared secret and the authentication
 468  *               vector.  We put them into MD5 in the reverse order from
 469  *               that used when encrypting passwords to RADIUS.
 470  *
 471  *************************************************************************/
 472 static void make_secret(uint8_t *digest, const uint8_t *vector,
 473                         const char *secret, const uint8_t *value)
 474 {
 475         FR_MD5_CTX context;
 476         int             i;
 477
 478         fr_MD5Init(&context);
 479         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 480         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 481         fr_MD5Final(digest, &context);
 482
 483         for ( i = 0; i < AUTH_VECTOR_LEN; i++ ) {
 484                 digest[i] ^= value[i];
 485         }
 486 }
 487
 488 #define MAX_PASS_LEN (128)
 489 static void make_passwd(uint8_t *output, size_t *outlen,
 490                         const uint8_t *input, size_t inlen,
 491                         const char *secret, const uint8_t *vector)
 492 {
 493         FR_MD5_CTX context, old;
 494         uint8_t digest[AUTH_VECTOR_LEN];
 495         uint8_t passwd[MAX_PASS_LEN];
 496         int     i, n;
 497         int     len;
 498
 499         /*
 500          *      If the length is zero, round it up.
 501          */
 502         len = inlen;
 503
 504         if (len > MAX_PASS_LEN) len = MAX_PASS_LEN;
 505
 506         memcpy(passwd, input, len);
 507         memset(passwd + len, 0, sizeof(passwd) - len);
 508
 509         if (len == 0) {
 510                 len = AUTH_PASS_LEN;
 511         }
 512
 513         else if ((len & 0x0f) != 0) {
 514                 len += 0x0f;
 515                 len &= ~0x0f;
 516         }
 517         *outlen = len;
 518
 519         fr_MD5Init(&context);
 520         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 521         old = context;
 522
 523         /*
 524          *      Do first pass.
 525          */
 526         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
 527
 528         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 529                 if (n > 0) {
 530                         context = old;
 531                         fr_MD5Update(&context,
 532                                        passwd + n - AUTH_PASS_LEN,
 533                                        AUTH_PASS_LEN);
 534                 }
 535
 536                 fr_MD5Final(digest, &context);
 537                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 538                         passwd[i + n] ^= digest[i];
 539                 }
 540         }
 541
 542         memcpy(output, passwd, len);
 543 }
 544
 545 static void make_tunnel_passwd(uint8_t *output, size_t *outlen,
 546                                const uint8_t *input, size_t inlen, size_t room,
 547                                const char *secret, const uint8_t *vector)
 548 {
 549         FR_MD5_CTX context, old;
 550         uint8_t digest[AUTH_VECTOR_LEN];
 551         uint8_t passwd[MAX_STRING_LEN + AUTH_VECTOR_LEN];
 552         int     i, n;
 553         int     len;
 554
 555         /*
 556          *      Be paranoid.
 557          */
 558         if (room > 253) room = 253;
 559
 560         /*
 561          *      Account for 2 bytes of the salt, and round the room
 562          *      available down to the nearest multiple of 16.  Then,
 563          *      subtract one from that to account for the length byte,
 564          *      and the resulting number is the upper bound on the data
 565          *      to copy.
 566          *
 567          *      We could short-cut this calculation just be forcing
 568          *      inlen to be no more than 239.  It would work for all
 569          *      VSA's, as we don't pack multiple VSA's into one
 570          *      attribute.
 571          *
 572          *      However, this calculation is more general, if a little
 573          *      complex.  And it will work in the future for all possible
 574          *      kinds of weird attribute packing.
 575          */
 576         room -= 2;
 577         room -= (room & 0x0f);
 578         room--;
 579
 580         if (inlen > room) inlen = room;
 581
 582         /*
 583          *      Length of the encrypted data is password length plus
 584          *      one byte for the length of the password.
 585          */
 586         len = inlen + 1;
 587         if ((len & 0x0f) != 0) {
 588                 len += 0x0f;
 589                 len &= ~0x0f;
 590         }
 591         *outlen = len + 2;      /* account for the salt */
 592
 593         /*
 594          *      Copy the password over.
 595          */
 596         memcpy(passwd + 3, input, inlen);
 597         memset(passwd + 3 + inlen, 0, sizeof(passwd) - 3 - inlen);
 598
 599         /*
 600          *      Generate salt.  The RFC's say:
 601          *
 602          *      The high bit of salt[0] must be set, each salt in a
 603          *      packet should be unique, and they should be random
 604          *
 605          *      So, we set the high bit, add in a counter, and then
 606          *      add in some CSPRNG data.  should be OK..
 607          */
 608         passwd[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
 609                      (fr_rand() & 0x07));
 610         passwd[1] = fr_rand();
 611         passwd[2] = inlen;      /* length of the password string */
 612
 613         fr_MD5Init(&context);
 614         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
 615         old = context;
 616
 617         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
 618         fr_MD5Update(&context, &passwd[0], 2);
 619
 620         for (n = 0; n < len; n += AUTH_PASS_LEN) {
 621                 if (n > 0) {
 622                         context = old;
 623                         fr_MD5Update(&context,
 624                                        passwd + 2 + n - AUTH_PASS_LEN,
 625                                        AUTH_PASS_LEN);
 626                 }
 627
 628                 fr_MD5Final(digest, &context);
 629
 630                 for (i = 0; i < AUTH_PASS_LEN; i++) {
 631                         passwd[i + 2 + n] ^= digest[i];
 632                 }
 633         }
 634         memcpy(output, passwd, len + 2);
 635 }
 636
 637 /*
 638  *      Returns the end of the data.
 639  */
 640 static int vp2data(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 641                    const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 642                    size_t room)
 643 {
 644         uint32_t lvalue;
 645         size_t len;
 646         const uint8_t *data;
 647         uint8_t *ptr = start;
 648         uint8_t array[4];
 649
 650         /*
 651          *      Set up the default sources for the data.
 652          */
 653         data = vp->vp_octets;
 654         len = vp->length;
 655
 656         switch(vp->type) {
 657         case PW_TYPE_STRING:
 658         case PW_TYPE_OCTETS:
 659         case PW_TYPE_IFID:
 660         case PW_TYPE_IPV6ADDR:
 661         case PW_TYPE_IPV6PREFIX:
 662         case PW_TYPE_ABINARY:
 663                 /* nothing more to do */
 664                 break;
 665
 666         case PW_TYPE_BYTE:
 667                 len = 1;        /* just in case */
 668                 array[0] = vp->vp_integer & 0xff;
 669                 data = array;
 670                 break;
 671
 672         case PW_TYPE_SHORT:
 673                 len = 2;        /* just in case */
 674                 array[0] = (vp->vp_integer >> 8) & 0xff;
 675                 array[1] = vp->vp_integer & 0xff;
 676                 data = array;
 677                 break;
 678
 679         case PW_TYPE_INTEGER:
 680                 len = 4;        /* just in case */
 681                 lvalue = htonl(vp->vp_integer);
 682                 memcpy(array, &lvalue, sizeof(lvalue));
 683                 data = array;
 684                 break;
 685
 686         case PW_TYPE_IPADDR:
 687                 data = (const uint8_t *) &vp->vp_ipaddr;
 688                 len = 4;        /* just in case */
 689                 break;
 690
 691                 /*
 692                  *  There are no tagged date attributes.
 693                  */
 694         case PW_TYPE_DATE:
 695                 lvalue = htonl(vp->vp_date);
 696                 data = (const uint8_t *) &lvalue;
 697                 len = 4;        /* just in case */
 698                 break;
 699
 700         case PW_TYPE_SIGNED:
 701         {
 702                 int32_t slvalue;
 703
 704                 len = 4;        /* just in case */
 705                 slvalue = htonl(vp->vp_signed);
 706                 memcpy(array, &slvalue, sizeof(slvalue));
 707                 break;
 708         }
 709
 710         case PW_TYPE_TLV:
 711                 data = vp->vp_tlv;
 712                 if (!data) {
 713                         fr_strerror_printf("ERROR: Cannot encode NULL TLV");
 714                         return -1;
 715                 }
 716                 if (vp->length > room) return 0; /* can't chop TLVs to fit */
 717                 break;
 718
 719         default:                /* unknown type: ignore it */
 720                 fr_strerror_printf("ERROR: Unknown attribute type %d", vp->type);
 721                 return -1;
 722         }
 723
 724         /*
 725          *      Bound the data to the calling size
 726          */
 727         if (len > room) len = room;
 728
 729         /*
 730          *      Encrypt the various password styles
 731          *
 732          *      Attributes with encrypted values MUST be less than
 733          *      128 bytes long.
 734          */
 735         switch (vp->flags.encrypt) {
 736         case FLAG_ENCRYPT_USER_PASSWORD:
 737                 make_passwd(ptr, &len, data, len,
 738                             secret, packet->vector);
 739                 break;
 740
 741         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
 742                 lvalue = 0;
 743                 if (vp->flags.has_tag) lvalue = 1;
 744
 745                 /*
 746                  *      Check if there's enough room.  If there isn't,
 747                  *      we discard the attribute.
 748                  *
 749                  *      This is ONLY a problem if we have multiple VSA's
 750                  *      in one Vendor-Specific, though.
 751                  */
 752                 if (room < (18 + lvalue)) return 0;
 753
 754                 switch (packet->code) {
 755                 case PW_AUTHENTICATION_ACK:
 756                 case PW_AUTHENTICATION_REJECT:
 757                 case PW_ACCESS_CHALLENGE:
 758                 default:
 759                         if (!original) {
 760                                 fr_strerror_printf("ERROR: No request packet, cannot encrypt %s attribute in the vp.", vp->name);
 761                                 return -1;
 762                         }
 763
 764                         if (lvalue) ptr[0] = vp->flags.tag;
 765                         make_tunnel_passwd(ptr + lvalue, &len, data, len,
 766                                            room - lvalue,
 767                                            secret, original->vector);
 768                         break;
 769                 case PW_ACCOUNTING_REQUEST:
 770                 case PW_DISCONNECT_REQUEST:
 771                 case PW_COA_REQUEST:
 772                         ptr[0] = vp->flags.tag;
 773                         make_tunnel_passwd(ptr + 1, &len, data, len - 1, room,
 774                                            secret, packet->vector);
 775                         break;
 776                 }
 777                 break;
 778
 779                 /*
 780                  *      The code above ensures that this attribute
 781                  *      always fits.
 782                  */
 783         case FLAG_ENCRYPT_ASCEND_SECRET:
 784                 make_secret(ptr, packet->vector, secret, data);
 785                 len = AUTH_VECTOR_LEN;
 786                 break;
 787
 788
 789         default:
 790                 if (vp->flags.has_tag && TAG_VALID(vp->flags.tag)) {
 791                         if (vp->type == PW_TYPE_STRING) {
 792                                 if (len > (room - 1)) len = room - 1;
 793                                 ptr[0] = vp->flags.tag;
 794                                 ptr++;
 795                         } else if (vp->type == PW_TYPE_INTEGER) {
 796                                 array[0] = vp->flags.tag;
 797                         } /* else it can't be any other type */
 798                 }
 799                 memcpy(ptr, data, len);
 800                 break;
 801         } /* switch over encryption flags */
 802
 803         return len + (ptr - start);;
 804 }
 805
 806
 807 static int rad_vp2rfc(const RADIUS_PACKET *packet,
 808                       const RADIUS_PACKET *original,
 809                       const char *secret, const VALUE_PAIR *vp,
 810                       unsigned int attribute, uint8_t *ptr, size_t room)
 811 {
 812         int len;
 813
 814         if (room < 2) return 0;
 815
 816         ptr[0] = attribute & 0xff; /* NOT vp->attribute */
 817         ptr[1] = 2;
 818
 819         len = vp2data(packet, original, secret, vp, ptr + 2, room - 2);
 820         if (len < 0) return len;
 821
 822         ptr[1] += len;
 823
 824         return ptr[1];
 825 }
 826
 827 static int tlv2data(const RADIUS_PACKET *packet,
 828                     const RADIUS_PACKET *original,
 829                     const char *secret, const VALUE_PAIR *vp, int attribute,
 830                     uint8_t *ptr, size_t room)
 831 {
 832         int len;
 833
 834         if (room < 2) return 0;
 835         room -= 2;
 836
 837         ptr[0] = attribute & 0xff;
 838         ptr[1] = 2;
 839
 840         /*
 841          *      No more nested TLVs: pack the data.
 842          */
 843         if ((attribute & ~0xff) == 0) {
 844                 len = vp2data(packet, original, secret, vp, ptr + 2, room);
 845         } else {
 846                 len = tlv2data(packet, original, secret, vp, attribute >> 8,
 847                                ptr + 2, room);
 848         }
 849         if (len <= 0) return len;
 850
 851         ptr[1] += len;
 852
 853         return ptr[1];
 854 }
 855
 856 static int wimax2data(const RADIUS_PACKET *packet,
 857                       const RADIUS_PACKET *original,
 858                       const char *secret, const VALUE_PAIR *vp,
 859                       uint8_t *start, size_t room, uint8_t *ptr)
 860 {
 861         int len;
 862
 863         /*
 864          *      Offsets to Vendor-Specific length, and to length of
 865          *      WiMAX attribute.
 866          */
 867 #define VS_OFF (1)
 868 #define WM_OFF (7)
 869
 870         if (room < 1) return 0;
 871         room--;
 872
 873         /*
 874          *      Account for continuation bytes.  The caller has
 875          *      already accounting for the continuation byte in the
 876          *      Vendor-Specific "length" field.
 877          */
 878         start[WM_OFF]++;
 879         *(ptr++) = 0;
 880
 881         /*
 882          *      Chop everything to fit in one attribute.
 883          */
 884         if (room > (255 - 9)) room = (255 - 9);
 885
 886         /*
 887          *      The attribute contains TLVs that we have NOT decoded
 888          *      properly, OR it contains TLV that the user has encoded
 889          *      manually.  If it has no data, OR it's too long,
 890          *      discard it.  We're not going to walk through its
 891          *      contents trying to figure out how to chop it across
 892          *      multiple continuations.
 893          */
 894         if (vp->flags.has_tlv && (!vp->vp_tlv || (vp->length > room))) {
 895                 return 0;
 896         }
 897
 898         /*
 899          *      The attribute is a top-level integer, ipaddr, etc.
 900          *      Encode it.
 901          */
 902         if (!vp->flags.is_tlv) {
 903                 len = vp2data(packet, original, secret, vp, ptr, room);
 904         } else {
 905                 len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
 906                                ptr, room);
 907         }
 908
 909         if (len <= 0) return len;
 910
 911         start[VS_OFF] += len;
 912         start[WM_OFF] += len;
 913
 914         return start[VS_OFF];
 915 }
 916
 917
 918 /*
 919  *      Parse a data structure into a RADIUS attribute.
 920  */
 921 int rad_vp2attr(const RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 922                 const char *secret, const VALUE_PAIR *vp, uint8_t *start,
 923                 size_t room)
 924 {
 925         int len;
 926         uint32_t lvalue;
 927         uint8_t *ptr;
 928         DICT_VENDOR *dv;
 929
 930         /*
 931          *      RFC format attributes take the fast path.
 932          */
 933         if (vp->vendor == 0) {
 934                 len = rad_vp2rfc(packet, original, secret, vp,
 935                                  vp->attribute, start, room);
 936                 if (len < 0) return -1;
 937
 938                 /*
 939                  *      RFC 2865 section 5 says that zero-length
 940                  *      attributes MUST NOT be sent.
 941                  *
 942                  *      ... and the WiMAX forum ignores
 943                  *      this... because of one vendor.  Don't they
 944                  *      have anything better to do with their time?
 945                  */
 946                 if ((len == 0) &&
 947                     (vp->attribute != PW_CHARGEABLE_USER_IDENTITY)) return 0;
 948
 949                 return len;
 950
 951         }
 952
 953         /*
 954          *      Not enough room for:
 955          *              attr, len, vendor-id, vsa, vsalen
 956          */
 957         if (room < 8) return 0;
 958
 959         /*
 960          *      Build the Vendor-Specific header
 961          */
 962         ptr = start;
 963         *ptr++ = PW_VENDOR_SPECIFIC;
 964         *ptr++ = 6;
 965         room -= 6;
 966         lvalue = htonl(vp->vendor);
 967         memcpy(ptr, &lvalue, 4);
 968         ptr += 4;
 969
 970         /*
 971          *      Unknown vendors, and type=1,length=1,no-continuation
 972          *      are RFC format attributes.
 973          */
 974         dv = dict_vendorbyvalue(vp->vendor);
 975         if (!dv ||
 976             ((dv->type == 1) && (dv->length = 1) && !dv->flags)) {
 977                 len = rad_vp2rfc(packet, original, secret, vp,
 978                                  vp->attribute, ptr, room);
 979                 if (len <= 0) return len;
 980
 981                 start[1] += len;
 982                 return start[1];
 983         }
 984
 985         if (room < (dv->type + dv->length + dv->flags)) return 0;
 986         room -= (dv->type + dv->length + dv->flags);
 987         start[1] += (dv->type + dv->length + dv->flags);
 988
 989         switch (dv->type) {
 990                 case 1:
 991                         ptr[0] = (vp->attribute & 0xFF);
 992                         break;
 993
 994                 case 2:
 995                         ptr[0] = ((vp->attribute >> 8) & 0xFF);
 996                         ptr[1] = (vp->attribute & 0xFF);
 997                         break;
 998
 999                 case 4:
1000                         ptr[0] = 0;
1001                         ptr[1] = ((vp->attribute >> 16) & 0xFF);
1002                         ptr[2] = ((vp->attribute >> 8) & 0xFF);
1003                         ptr[3] = (vp->attribute & 0xFF);
1004                         break;
1005
1006                 default:
1007                         return 0; /* silently discard it */
1008         }
1009         ptr += dv->type;
1010
1011         switch (dv->length) {
1012         case 0:
1013                 break;
1014         case 1:
1015                 ptr[0] = dv->type + 1;
1016                 break;
1017         case 2:
1018                 ptr[0] = 0;
1019                 ptr[1] = dv->type + 2;
1020                 break;
1021
1022         default:
1023                 return 0; /* silently discard it */
1024         }
1025         ptr += dv->length;
1026
1027         /*
1028          *      WiMAX attributes take their own path through the
1029          *      system.
1030          */
1031         if (dv->flags) return wimax2data(packet, original, secret, vp,
1032                                          start, room, ptr);
1033
1034         len = vp2data(packet, original, secret, vp, ptr, room);
1035         if (len <= 0) return len;
1036
1037         if (dv->length != 0) ptr[-1] += len;
1038
1039         start[1] += len;
1040
1041         return start[1];
1042 }
1043
1044 /*
1045  *  Swap 123a -> 0321
1046  */
1047 #define REORDER(x) ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | ((x & 0xff000000 >> 24))
1048
1049
1050 /*
1051  *      Encode a WiMAX sub-TLV.  It must NOT be called for WiMAX
1052  *      attributes that are of type integer, string, etc.
1053  */
1054 static int rad_encode_wimax(const RADIUS_PACKET *packet,
1055                             const RADIUS_PACKET *original,
1056                             const char *secret, VALUE_PAIR *reply,
1057                             uint8_t *start, size_t room)
1058 {
1059         int len, redo;
1060         uint32_t lvalue;
1061         uint8_t *ptr = start, *vsa = start;
1062         uint32_t maxattr;
1063         VALUE_PAIR *vp = reply;
1064
1065         /*
1066          *      Swap the order of the WiMAX hacks, to make later
1067          *      comparisons easier.
1068          */
1069         maxattr = REORDER(vp->attribute);
1070
1071         /*
1072          *      Build the Vendor-Specific header
1073          */
1074         ptr = start;
1075         redo = 0;
1076
1077 redo_vsa:
1078         vsa = ptr;
1079
1080         if (room < 9) return 0;
1081         *ptr++ = PW_VENDOR_SPECIFIC;
1082         *ptr++ = 9;
1083         room -= 9;
1084         lvalue = htonl(vp->vendor);
1085         memcpy(ptr, &lvalue, 4);
1086         ptr += 4;
1087         *(ptr++) = vp->attribute & 0xff;
1088         *(ptr++) = 3;
1089         *(ptr++) = 0;           /* continuation */
1090         room -= 9;
1091
1092 redo_tlv:
1093         len = tlv2data(packet, original, secret, vp, vp->attribute >> 8,
1094                        ptr, room);
1095         if (len < 0) return len;
1096
1097         /*
1098          *      Not enough room.  Do a continuation.
1099          */
1100         if ((len == 0) || ((vsa[VS_OFF] + len) > 255)) {
1101                 if (redo) return (start - vsa);
1102
1103                 vsa[8] = 0x80;
1104                 redo = 1;
1105                 goto redo_vsa;
1106         }
1107         redo = 0;
1108
1109         ptr += len;
1110         vsa[VS_OFF] += len;
1111         vsa[WM_OFF] += len;
1112
1113         vp->flags.encoded = 1;
1114         vp = vp->next;
1115
1116         /*
1117          *      Look at the NEXT tlv.  Ensure that we encode
1118          *      attributes into a common VSA *only* if they are for
1119          *      the same WiMAX VSA, AND if the TLVs are in numerically
1120          *      increasing order.
1121          */
1122         if (vp && vp->flags.is_tlv && (reply->vendor == vp->vendor) &&
1123             ((reply->attribute & 0xff) == (vp->attribute & 0xff))) {
1124                 uint32_t attr;
1125
1126                 attr = REORDER(vp->attribute);
1127                 if (attr >= maxattr) {
1128                         maxattr = attr;
1129                         goto redo_tlv;
1130                 }
1131         }
1132
1133         return ptr - start;
1134 }
1135
1136
1137 /*
1138  *      Encode a packet.
1139  */
1140 int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1141                const char *secret)
1142 {
1143         radius_packet_t *hdr;
1144         uint8_t         *ptr;
1145         uint16_t        total_length;
1146         int             len;
1147         VALUE_PAIR      *reply;
1148         const char      *what;
1149         char            ip_buffer[128];
1150
1151         /*
1152          *      A 4K packet, aligned on 64-bits.
1153          */
1154         uint64_t        data[MAX_PACKET_LEN / sizeof(uint64_t)];
1155
1156         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1157                 what = fr_packet_codes[packet->code];
1158         } else {
1159                 what = "Reply";
1160         }
1161
1162         DEBUG("Sending %s of id %d to %s port %d\n",
1163               what, packet->id,
1164               inet_ntop(packet->dst_ipaddr.af,
1165                         &packet->dst_ipaddr.ipaddr,
1166                         ip_buffer, sizeof(ip_buffer)),
1167               packet->dst_port);
1168
1169         /*
1170          *      Double-check some things based on packet code.
1171          */
1172         switch (packet->code) {
1173         case PW_AUTHENTICATION_ACK:
1174         case PW_AUTHENTICATION_REJECT:
1175         case PW_ACCESS_CHALLENGE:
1176                 if (!original) {
1177                         fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1178                         return -1;
1179                 }
1180                 break;
1181
1182                 /*
1183                  *      These packet vectors start off as all zero.
1184                  */
1185         case PW_ACCOUNTING_REQUEST:
1186         case PW_DISCONNECT_REQUEST:
1187         case PW_COA_REQUEST:
1188                 memset(packet->vector, 0, sizeof(packet->vector));
1189                 break;
1190
1191         default:
1192                 break;
1193         }
1194
1195         /*
1196          *      Use memory on the stack, until we know how
1197          *      large the packet will be.
1198          */
1199         hdr = (radius_packet_t *) data;
1200
1201         /*
1202          *      Build standard header
1203          */
1204         hdr->code = packet->code;
1205         hdr->id = packet->id;
1206
1207         memcpy(hdr->vector, packet->vector, sizeof(hdr->vector));
1208
1209         total_length = AUTH_HDR_LEN;
1210
1211         /*
1212          *      Load up the configuration values for the user
1213          */
1214         ptr = hdr->data;
1215         packet->offset = 0;
1216
1217         /*
1218          *      FIXME: Loop twice over the reply list.  The first time,
1219          *      calculate the total length of data.  The second time,
1220          *      allocate the memory, and fill in the VP's.
1221          *
1222          *      Hmm... this may be slower than just doing a small
1223          *      memcpy.
1224          */
1225
1226         /*
1227          *      Loop over the reply attributes for the packet.
1228          */
1229         for (reply = packet->vps; reply; reply = reply->next) {
1230                 /*
1231                  *      Ignore non-wire attributes
1232                  */
1233                 if ((reply->vendor == 0) &&
1234                     ((reply->attribute & 0xFFFF) > 0xff)) {
1235 #ifndef NDEBUG
1236                         /*
1237                          *      Permit the admin to send BADLY formatted
1238                          *      attributes with a debug build.
1239                          */
1240                         if (reply->attribute == PW_RAW_ATTRIBUTE) {
1241                                 memcpy(ptr, reply->vp_octets, reply->length);
1242                                 len = reply->length;
1243                                 goto next;
1244                         }
1245 #endif
1246                         continue;
1247                 }
1248
1249                 /*
1250                  *      Set the Message-Authenticator to the correct
1251                  *      length and initial value.
1252                  */
1253                 if (reply->attribute == PW_MESSAGE_AUTHENTICATOR) {
1254                         reply->length = AUTH_VECTOR_LEN;
1255                         memset(reply->vp_strvalue, 0, AUTH_VECTOR_LEN);
1256
1257                         /*
1258                          *      Cache the offset to the
1259                          *      Message-Authenticator
1260                          */
1261                         packet->offset = total_length;
1262                 }
1263
1264                 /*
1265                  *      Print out ONLY the attributes which
1266                  *      we're sending over the wire, and print
1267                  *      them out BEFORE they're encrypted.
1268                  */
1269                 debug_pair(reply);
1270
1271                 /*
1272                  *      Skip attributes that are encoded.
1273                  */
1274                 if (reply->flags.encoded) continue;
1275
1276                 if (reply->flags.is_tlv) {
1277                         len = rad_encode_wimax(packet, original, secret,
1278                                                reply, ptr,
1279                                                ((uint8_t *) data) + sizeof(data) - ptr);
1280                 } else {
1281
1282                         len = rad_vp2attr(packet, original, secret, reply, ptr,
1283                                           ((uint8_t *) data) + sizeof(data) - ptr);
1284                 }
1285
1286                 if (len < 0) return -1;
1287
1288         next:
1289                 ptr += len;
1290                 total_length += len;
1291         } /* done looping over all attributes */
1292
1293         /*
1294          *      Fill in the rest of the fields, and copy the data over
1295          *      from the local stack to the newly allocated memory.
1296          *
1297          *      Yes, all this 'memcpy' is slow, but it means
1298          *      that we only allocate the minimum amount of
1299          *      memory for a request.
1300          */
1301         packet->data_len = total_length;
1302         packet->data = (uint8_t *) malloc(packet->data_len);
1303         if (!packet->data) {
1304                 fr_strerror_printf("Out of memory");
1305                 return -1;
1306         }
1307
1308         memcpy(packet->data, hdr, packet->data_len);
1309         hdr = (radius_packet_t *) packet->data;
1310
1311         total_length = htons(total_length);
1312         memcpy(hdr->length, &total_length, sizeof(total_length));
1313
1314         return 0;
1315 }
1316
1317
1318 /*
1319  *      Sign a previously encoded packet.
1320  */
1321 int rad_sign(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1322              const char *secret)
1323 {
1324         radius_packet_t *hdr = (radius_packet_t *)packet->data;
1325
1326         /*
1327          *      It wasn't assigned an Id, this is bad!
1328          */
1329         if (packet->id < 0) {
1330                 fr_strerror_printf("ERROR: RADIUS packets must be assigned an Id.");
1331                 return -1;
1332         }
1333
1334         if (!packet->data || (packet->data_len < AUTH_HDR_LEN) ||
1335             (packet->offset < 0)) {
1336                 fr_strerror_printf("ERROR: You must call rad_encode() before rad_sign()");
1337                 return -1;
1338         }
1339
1340         /*
1341          *      If there's a Message-Authenticator, update it
1342          *      now, BEFORE updating the authentication vector.
1343          */
1344         if (packet->offset > 0) {
1345                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
1346
1347                 switch (packet->code) {
1348                 case PW_ACCOUNTING_REQUEST:
1349                 case PW_ACCOUNTING_RESPONSE:
1350                 case PW_DISCONNECT_REQUEST:
1351                 case PW_DISCONNECT_ACK:
1352                 case PW_DISCONNECT_NAK:
1353                 case PW_COA_REQUEST:
1354                 case PW_COA_ACK:
1355                 case PW_COA_NAK:
1356                         memset(hdr->vector, 0, AUTH_VECTOR_LEN);
1357                         break;
1358
1359                 case PW_AUTHENTICATION_ACK:
1360                 case PW_AUTHENTICATION_REJECT:
1361                 case PW_ACCESS_CHALLENGE:
1362                         if (!original) {
1363                                 fr_strerror_printf("ERROR: Cannot sign response packet without a request packet.");
1364                                 return -1;
1365                         }
1366                         memcpy(hdr->vector, original->vector,
1367                                AUTH_VECTOR_LEN);
1368                         break;
1369
1370                 default:        /* others have vector already set to zero */
1371                         break;
1372
1373                 }
1374
1375                 /*
1376                  *      Set the authentication vector to zero,
1377                  *      calculate the signature, and put it
1378                  *      into the Message-Authenticator
1379                  *      attribute.
1380                  */
1381                 fr_hmac_md5(packet->data, packet->data_len,
1382                             (const uint8_t *) secret, strlen(secret),
1383                             calc_auth_vector);
1384                 memcpy(packet->data + packet->offset + 2,
1385                        calc_auth_vector, AUTH_VECTOR_LEN);
1386
1387                 /*
1388                  *      Copy the original request vector back
1389                  *      to the raw packet.
1390                  */
1391                 memcpy(hdr->vector, packet->vector, AUTH_VECTOR_LEN);
1392         }
1393
1394         /*
1395          *      Switch over the packet code, deciding how to
1396          *      sign the packet.
1397          */
1398         switch (packet->code) {
1399                 /*
1400                  *      Request packets are not signed, bur
1401                  *      have a random authentication vector.
1402                  */
1403         case PW_AUTHENTICATION_REQUEST:
1404         case PW_STATUS_SERVER:
1405                 break;
1406
1407                 /*
1408                  *      Reply packets are signed with the
1409                  *      authentication vector of the request.
1410                  */
1411         default:
1412                 {
1413                         uint8_t digest[16];
1414
1415                         FR_MD5_CTX      context;
1416                         fr_MD5Init(&context);
1417                         fr_MD5Update(&context, packet->data, packet->data_len);
1418                         fr_MD5Update(&context, (const uint8_t *) secret,
1419                                      strlen(secret));
1420                         fr_MD5Final(digest, &context);
1421
1422                         memcpy(hdr->vector, digest, AUTH_VECTOR_LEN);
1423                         memcpy(packet->vector, digest, AUTH_VECTOR_LEN);
1424                         break;
1425                 }
1426         }/* switch over packet codes */
1427
1428         return 0;
1429 }
1430
1431 /*
1432  *      Reply to the request.  Also attach
1433  *      reply attribute value pairs and any user message provided.
1434  */
1435 int rad_send(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
1436              const char *secret)
1437 {
1438         VALUE_PAIR              *reply;
1439         const char              *what;
1440         char                    ip_buffer[128];
1441
1442         /*
1443          *      Maybe it's a fake packet.  Don't send it.
1444          */
1445         if (!packet || (packet->sockfd < 0)) {
1446                 return 0;
1447         }
1448
1449         if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1450                 what = fr_packet_codes[packet->code];
1451         } else {
1452                 what = "Reply";
1453         }
1454
1455         /*
1456          *  First time through, allocate room for the packet
1457          */
1458         if (!packet->data) {
1459                 /*
1460                  *      Encode the packet.
1461                  */
1462                 if (rad_encode(packet, original, secret) < 0) {
1463                         return -1;
1464                 }
1465
1466                 /*
1467                  *      Re-sign it, including updating the
1468                  *      Message-Authenticator.
1469                  */
1470                 if (rad_sign(packet, original, secret) < 0) {
1471                         return -1;
1472                 }
1473
1474                 /*
1475                  *      If packet->data points to data, then we print out
1476                  *      the VP list again only for debugging.
1477                  */
1478         } else if (fr_debug_flag) {
1479                 DEBUG("Sending %s of id %d to %s port %d\n", what, packet->id,
1480                       inet_ntop(packet->dst_ipaddr.af,
1481                                 &packet->dst_ipaddr.ipaddr,
1482                                 ip_buffer, sizeof(ip_buffer)),
1483                       packet->dst_port);
1484
1485                 for (reply = packet->vps; reply; reply = reply->next) {
1486                         if ((reply->vendor == 0) &&
1487                             ((reply->attribute & 0xFFFF) > 0xff)) continue;
1488                         debug_pair(reply);
1489                 }
1490         }
1491
1492         /*
1493          *      And send it on it's way.
1494          */
1495         return rad_sendto(packet->sockfd, packet->data, packet->data_len, 0,
1496                           &packet->src_ipaddr, packet->src_port,
1497                           &packet->dst_ipaddr, packet->dst_port);
1498 }
1499
1500 /*
1501  *      Do a comparison of two authentication digests by comparing
1502  *      the FULL digest.  Otehrwise, the server can be subject to
1503  *      timing attacks that allow attackers find a valid message
1504  *      authenticator.
1505  *
1506  *      http://www.cs.rice.edu/~dwallach/pub/crosby-timing2009.pdf
1507  */
1508 static int digest_cmp(const uint8_t *a, const uint8_t *b, size_t length)
1509 {
1510         int result = 0;
1511         size_t i;
1512
1513         for (i = 0; i < length; i++) {
1514                 result |= a[i] ^ b[i];
1515         }
1516
1517         return result;          /* 0 is OK, !0 is !OK, just like memcmp */
1518 }
1519
1520
1521 /*
1522  *      Validates the requesting client NAS.  Calculates the
1523  *      signature based on the clients private key.
1524  */
1525 static int calc_acctdigest(RADIUS_PACKET *packet, const char *secret)
1526 {
1527         uint8_t         digest[AUTH_VECTOR_LEN];
1528         FR_MD5_CTX              context;
1529
1530         /*
1531          *      Zero out the auth_vector in the received packet.
1532          *      Then append the shared secret to the received packet,
1533          *      and calculate the MD5 sum. This must be the same
1534          *      as the original MD5 sum (packet->vector).
1535          */
1536         memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
1537
1538         /*
1539          *  MD5(packet + secret);
1540          */
1541         fr_MD5Init(&context);
1542         fr_MD5Update(&context, packet->data, packet->data_len);
1543         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1544         fr_MD5Final(digest, &context);
1545
1546         /*
1547          *      Return 0 if OK, 2 if not OK.
1548          */
1549         if (digest_cmp(digest, packet->vector, AUTH_VECTOR_LEN) != 0) return 2;
1550         return 0;
1551 }
1552
1553
1554 /*
1555  *      Validates the requesting client NAS.  Calculates the
1556  *      signature based on the clients private key.
1557  */
1558 static int calc_replydigest(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1559                             const char *secret)
1560 {
1561         uint8_t         calc_digest[AUTH_VECTOR_LEN];
1562         FR_MD5_CTX              context;
1563
1564         /*
1565          *      Very bad!
1566          */
1567         if (original == NULL) {
1568                 return 3;
1569         }
1570
1571         /*
1572          *  Copy the original vector in place.
1573          */
1574         memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
1575
1576         /*
1577          *  MD5(packet + secret);
1578          */
1579         fr_MD5Init(&context);
1580         fr_MD5Update(&context, packet->data, packet->data_len);
1581         fr_MD5Update(&context, (const uint8_t *) secret, strlen(secret));
1582         fr_MD5Final(calc_digest, &context);
1583
1584         /*
1585          *  Copy the packet's vector back to the packet.
1586          */
1587         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
1588
1589         /*
1590          *      Return 0 if OK, 2 if not OK.
1591          */
1592         if (digest_cmp(packet->vector, calc_digest, AUTH_VECTOR_LEN) != 0) return 2;
1593         return 0;
1594 }
1595
1596
1597 /*
1598  *      See if the data pointed to by PTR is a valid RADIUS packet.
1599  *
1600  *      packet is not 'const * const' because we may update data_len,
1601  *      if there's more data in the UDP packet than in the RADIUS packet.
1602  */
1603 int rad_packet_ok(RADIUS_PACKET *packet, int flags)
1604 {
1605         uint8_t                 *attr;
1606         int                     totallen;
1607         int                     count;
1608         radius_packet_t         *hdr;
1609         char                    host_ipaddr[128];
1610         int                     require_ma = 0;
1611         int                     seen_ma = 0;
1612         int                     num_attributes;
1613
1614         /*
1615          *      Check for packets smaller than the packet header.
1616          *
1617          *      RFC 2865, Section 3., subsection 'length' says:
1618          *
1619          *      "The minimum length is 20 ..."
1620          */
1621         if (packet->data_len < AUTH_HDR_LEN) {
1622                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (received %d < minimum %d)",
1623                            inet_ntop(packet->src_ipaddr.af,
1624                                      &packet->src_ipaddr.ipaddr,
1625                                      host_ipaddr, sizeof(host_ipaddr)),
1626                                    (int) packet->data_len, AUTH_HDR_LEN);
1627                 return 0;
1628         }
1629
1630         /*
1631          *      RFC 2865, Section 3., subsection 'length' says:
1632          *
1633          *      " ... and maximum length is 4096."
1634          */
1635         if (packet->data_len > MAX_PACKET_LEN) {
1636                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (received %d > maximum %d)",
1637                            inet_ntop(packet->src_ipaddr.af,
1638                                      &packet->src_ipaddr.ipaddr,
1639                                      host_ipaddr, sizeof(host_ipaddr)),
1640                                    (int) packet->data_len, MAX_PACKET_LEN);
1641                 return 0;
1642         }
1643
1644         /*
1645          *      Check for packets with mismatched size.
1646          *      i.e. We've received 128 bytes, and the packet header
1647          *      says it's 256 bytes long.
1648          */
1649         totallen = (packet->data[2] << 8) | packet->data[3];
1650         hdr = (radius_packet_t *)packet->data;
1651
1652         /*
1653          *      Code of 0 is not understood.
1654          *      Code of 16 or greate is not understood.
1655          */
1656         if ((hdr->code == 0) ||
1657             (hdr->code >= FR_MAX_PACKET_CODE)) {
1658                 fr_strerror_printf("WARNING: Bad RADIUS packet from host %s: unknown packet code%d ",
1659                            inet_ntop(packet->src_ipaddr.af,
1660                                      &packet->src_ipaddr.ipaddr,
1661                                      host_ipaddr, sizeof(host_ipaddr)),
1662                            hdr->code);
1663                 return 0;
1664         }
1665
1666         /*
1667          *      Message-Authenticator is required in Status-Server
1668          *      packets, otherwise they can be trivially forged.
1669          */
1670         if (hdr->code == PW_STATUS_SERVER) require_ma = 1;
1671
1672         /*
1673          *      It's also required if the caller asks for it.
1674          */
1675         if (flags) require_ma = 1;
1676
1677         /*
1678          *      Repeat the length checks.  This time, instead of
1679          *      looking at the data we received, look at the value
1680          *      of the 'length' field inside of the packet.
1681          *
1682          *      Check for packets smaller than the packet header.
1683          *
1684          *      RFC 2865, Section 3., subsection 'length' says:
1685          *
1686          *      "The minimum length is 20 ..."
1687          */
1688         if (totallen < AUTH_HDR_LEN) {
1689                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too short (length %d < minimum %d)",
1690                            inet_ntop(packet->src_ipaddr.af,
1691                                      &packet->src_ipaddr.ipaddr,
1692                                      host_ipaddr, sizeof(host_ipaddr)),
1693                            totallen, AUTH_HDR_LEN);
1694                 return 0;
1695         }
1696
1697         /*
1698          *      And again, for the value of the 'length' field.
1699          *
1700          *      RFC 2865, Section 3., subsection 'length' says:
1701          *
1702          *      " ... and maximum length is 4096."
1703          */
1704         if (totallen > MAX_PACKET_LEN) {
1705                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: too long (length %d > maximum %d)",
1706                            inet_ntop(packet->src_ipaddr.af,
1707                                      &packet->src_ipaddr.ipaddr,
1708                                      host_ipaddr, sizeof(host_ipaddr)),
1709                            totallen, MAX_PACKET_LEN);
1710                 return 0;
1711         }
1712
1713         /*
1714          *      RFC 2865, Section 3., subsection 'length' says:
1715          *
1716          *      "If the packet is shorter than the Length field
1717          *      indicates, it MUST be silently discarded."
1718          *
1719          *      i.e. No response to the NAS.
1720          */
1721         if (packet->data_len < totallen) {
1722                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: received %d octets, packet length says %d",
1723                            inet_ntop(packet->src_ipaddr.af,
1724                                      &packet->src_ipaddr.ipaddr,
1725                                      host_ipaddr, sizeof(host_ipaddr)),
1726                                    (int) packet->data_len, totallen);
1727                 return 0;
1728         }
1729
1730         /*
1731          *      RFC 2865, Section 3., subsection 'length' says:
1732          *
1733          *      "Octets outside the range of the Length field MUST be
1734          *      treated as padding and ignored on reception."
1735          */
1736         if (packet->data_len > totallen) {
1737                 /*
1738                  *      We're shortening the packet below, but just
1739                  *      to be paranoid, zero out the extra data.
1740                  */
1741                 memset(packet->data + totallen, 0, packet->data_len - totallen);
1742                 packet->data_len = totallen;
1743         }
1744
1745         /*
1746          *      Walk through the packet's attributes, ensuring that
1747          *      they add up EXACTLY to the size of the packet.
1748          *
1749          *      If they don't, then the attributes either under-fill
1750          *      or over-fill the packet.  Any parsing of the packet
1751          *      is impossible, and will result in unknown side effects.
1752          *
1753          *      This would ONLY happen with buggy RADIUS implementations,
1754          *      or with an intentional attack.  Either way, we do NOT want
1755          *      to be vulnerable to this problem.
1756          */
1757         attr = hdr->data;
1758         count = totallen - AUTH_HDR_LEN;
1759         num_attributes = 0;
1760
1761         while (count > 0) {
1762                 /*
1763                  *      Attribute number zero is NOT defined.
1764                  */
1765                 if (attr[0] == 0) {
1766                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Invalid attribute 0",
1767                                    inet_ntop(packet->src_ipaddr.af,
1768                                              &packet->src_ipaddr.ipaddr,
1769                                              host_ipaddr, sizeof(host_ipaddr)));
1770                         return 0;
1771                 }
1772
1773                 /*
1774                  *      Attributes are at LEAST as long as the ID & length
1775                  *      fields.  Anything shorter is an invalid attribute.
1776                  */
1777                 if (attr[1] < 2) {
1778                         fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: attribute %d too short",
1779                                    inet_ntop(packet->src_ipaddr.af,
1780                                              &packet->src_ipaddr.ipaddr,
1781                                              host_ipaddr, sizeof(host_ipaddr)),
1782                                    attr[0]);
1783                         return 0;
1784                 }
1785
1786                 /*
1787                  *      Sanity check the attributes for length.
1788                  */
1789                 switch (attr[0]) {
1790                 default:        /* don't do anything by default */
1791                         break;
1792
1793                         /*
1794                          *      If there's an EAP-Message, we require
1795                          *      a Message-Authenticator.
1796                          */
1797                 case PW_EAP_MESSAGE:
1798                         require_ma = 1;
1799                         break;
1800
1801                 case PW_MESSAGE_AUTHENTICATOR:
1802                         if (attr[1] != 2 + AUTH_VECTOR_LEN) {
1803                                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
1804                                            inet_ntop(packet->src_ipaddr.af,
1805                                                      &packet->src_ipaddr.ipaddr,
1806                                                      host_ipaddr, sizeof(host_ipaddr)),
1807                                            attr[1] - 2);
1808                                 return 0;
1809                         }
1810                         seen_ma = 1;
1811                         break;
1812                 }
1813
1814                 /*
1815                  *      FIXME: Look up the base 255 attributes in the
1816                  *      dictionary, and switch over their type.  For
1817                  *      integer/date/ip, the attribute length SHOULD
1818                  *      be 6.
1819                  */
1820                 count -= attr[1];       /* grab the attribute length */
1821                 attr += attr[1];
1822                 num_attributes++;       /* seen one more attribute */
1823         }
1824
1825         /*
1826          *      If the attributes add up to a packet, it's allowed.
1827          *
1828          *      If not, we complain, and throw the packet away.
1829          */
1830         if (count != 0) {
1831                 fr_strerror_printf("WARNING: Malformed RADIUS packet from host %s: packet attributes do NOT exactly fill the packet",
1832                            inet_ntop(packet->src_ipaddr.af,
1833                                      &packet->src_ipaddr.ipaddr,
1834                                      host_ipaddr, sizeof(host_ipaddr)));
1835                 return 0;
1836         }
1837
1838         /*
1839          *      If we're configured to look for a maximum number of
1840          *      attributes, and we've seen more than that maximum,
1841          *      then throw the packet away, as a possible DoS.
1842          */
1843         if ((fr_max_attributes > 0) &&
1844             (num_attributes > fr_max_attributes)) {
1845                 fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
1846                            inet_ntop(packet->src_ipaddr.af,
1847                                      &packet->src_ipaddr.ipaddr,
1848                                      host_ipaddr, sizeof(host_ipaddr)),
1849                            num_attributes, fr_max_attributes);
1850                 return 0;
1851         }
1852
1853         /*
1854          *      http://www.freeradius.org/rfc/rfc2869.html#EAP-Message
1855          *
1856          *      A packet with an EAP-Message attribute MUST also have
1857          *      a Message-Authenticator attribute.
1858          *
1859          *      A Message-Authenticator all by itself is OK, though.
1860          *
1861          *      Similarly, Status-Server packets MUST contain
1862          *      Message-Authenticator attributes.
1863          */
1864         if (require_ma && ! seen_ma) {
1865                 fr_strerror_printf("WARNING: Insecure packet from host %s:  Packet does not contain required Message-Authenticator attribute",
1866                            inet_ntop(packet->src_ipaddr.af,
1867                                      &packet->src_ipaddr.ipaddr,
1868                                      host_ipaddr, sizeof(host_ipaddr)));
1869                 return 0;
1870         }
1871
1872         /*
1873          *      Fill RADIUS header fields
1874          */
1875         packet->code = hdr->code;
1876         packet->id = hdr->id;
1877         memcpy(packet->vector, hdr->vector, AUTH_VECTOR_LEN);
1878
1879         return 1;
1880 }
1881
1882
1883 /*
1884  *      Receive UDP client requests, and fill in
1885  *      the basics of a RADIUS_PACKET structure.
1886  */
1887 RADIUS_PACKET *rad_recv(int fd, int flags)
1888 {
1889         int sock_flags = 0;
1890         RADIUS_PACKET           *packet;
1891
1892         /*
1893          *      Allocate the new request data structure
1894          */
1895         if ((packet = malloc(sizeof(*packet))) == NULL) {
1896                 fr_strerror_printf("out of memory");
1897                 return NULL;
1898         }
1899         memset(packet, 0, sizeof(*packet));
1900
1901         if (flags & 0x02) {
1902                 sock_flags = MSG_PEEK;
1903                 flags &= ~0x02;
1904         }
1905
1906         packet->data_len = rad_recvfrom(fd, &packet->data, sock_flags,
1907                                         &packet->src_ipaddr, &packet->src_port,
1908                                         &packet->dst_ipaddr, &packet->dst_port);
1909
1910         /*
1911          *      Check for socket errors.
1912          */
1913         if (packet->data_len < 0) {
1914                 fr_strerror_printf("Error receiving packet: %s", strerror(errno));
1915                 /* packet->data is NULL */
1916                 free(packet);
1917                 return NULL;
1918         }
1919
1920         /*
1921          *      If the packet is too big, then rad_recvfrom did NOT
1922          *      allocate memory.  Instead, it just discarded the
1923          *      packet.
1924          */
1925         if (packet->data_len > MAX_PACKET_LEN) {
1926                 fr_strerror_printf("Discarding packet: Larger than RFC limitation of 4096 bytes.");
1927                 /* packet->data is NULL */
1928                 free(packet);
1929                 return NULL;
1930         }
1931
1932         /*
1933          *      Read no data.  Continue.
1934          *      This check is AFTER the MAX_PACKET_LEN check above, because
1935          *      if the packet is larger than MAX_PACKET_LEN, we also have
1936          *      packet->data == NULL
1937          */
1938         if ((packet->data_len == 0) || !packet->data) {
1939                 fr_strerror_printf("Empty packet: Socket is not ready.");
1940                 free(packet);
1941                 return NULL;
1942         }
1943
1944         /*
1945          *      See if it's a well-formed RADIUS packet.
1946          */
1947         if (!rad_packet_ok(packet, flags)) {
1948                 rad_free(&packet);
1949                 return NULL;
1950         }
1951
1952         /*
1953          *      Remember which socket we read the packet from.
1954          */
1955         packet->sockfd = fd;
1956
1957         /*
1958          *      FIXME: Do even more filtering by only permitting
1959          *      certain IP's.  The problem is that we don't know
1960          *      how to do this properly for all possible clients...
1961          */
1962
1963         /*
1964          *      Explicitely set the VP list to empty.
1965          */
1966         packet->vps = NULL;
1967
1968         if (fr_debug_flag) {
1969                 char host_ipaddr[128];
1970
1971                 if ((packet->code > 0) && (packet->code < FR_MAX_PACKET_CODE)) {
1972                         DEBUG("rad_recv: %s packet from host %s port %d",
1973                               fr_packet_codes[packet->code],
1974                               inet_ntop(packet->src_ipaddr.af,
1975                                         &packet->src_ipaddr.ipaddr,
1976                                         host_ipaddr, sizeof(host_ipaddr)),
1977                               packet->src_port);
1978                 } else {
1979                         DEBUG("rad_recv: Packet from host %s port %d code=%d",
1980                               inet_ntop(packet->src_ipaddr.af,
1981                                         &packet->src_ipaddr.ipaddr,
1982                                         host_ipaddr, sizeof(host_ipaddr)),
1983                               packet->src_port,
1984                               packet->code);
1985                 }
1986                 DEBUG(", id=%d, length=%d\n",
1987                       packet->id, (int) packet->data_len);
1988         }
1989
1990         return packet;
1991 }
1992
1993
1994 /*
1995  *      Verify the signature of a packet.
1996  */
1997 int rad_verify(RADIUS_PACKET *packet, RADIUS_PACKET *original,
1998                const char *secret)
1999 {
2000         uint8_t                 *ptr;
2001         int                     length;
2002         int                     attrlen;
2003
2004         if (!packet || !packet->data) return -1;
2005
2006         /*
2007          *      Before we allocate memory for the attributes, do more
2008          *      sanity checking.
2009          */
2010         ptr = packet->data + AUTH_HDR_LEN;
2011         length = packet->data_len - AUTH_HDR_LEN;
2012         while (length > 0) {
2013                 uint8_t msg_auth_vector[AUTH_VECTOR_LEN];
2014                 uint8_t calc_auth_vector[AUTH_VECTOR_LEN];
2015
2016                 attrlen = ptr[1];
2017
2018                 switch (ptr[0]) {
2019                 default:        /* don't do anything. */
2020                         break;
2021
2022                         /*
2023                          *      Note that more than one Message-Authenticator
2024                          *      attribute is invalid.
2025                          */
2026                 case PW_MESSAGE_AUTHENTICATOR:
2027                         memcpy(msg_auth_vector, &ptr[2], sizeof(msg_auth_vector));
2028                         memset(&ptr[2], 0, AUTH_VECTOR_LEN);
2029
2030                         switch (packet->code) {
2031                         default:
2032                                 break;
2033
2034                         case PW_ACCOUNTING_REQUEST:
2035                         case PW_ACCOUNTING_RESPONSE:
2036                         case PW_DISCONNECT_REQUEST:
2037                         case PW_DISCONNECT_ACK:
2038                         case PW_DISCONNECT_NAK:
2039                         case PW_COA_REQUEST:
2040                         case PW_COA_ACK:
2041                         case PW_COA_NAK:
2042                                 memset(packet->data + 4, 0, AUTH_VECTOR_LEN);
2043                                 break;
2044
2045                         case PW_AUTHENTICATION_ACK:
2046                         case PW_AUTHENTICATION_REJECT:
2047                         case PW_ACCESS_CHALLENGE:
2048                                 if (!original) {
2049                                         fr_strerror_printf("ERROR: Cannot validate Message-Authenticator in response packet without a request packet.");
2050                                         return -1;
2051                                 }
2052                                 memcpy(packet->data + 4, original->vector, AUTH_VECTOR_LEN);
2053                                 break;
2054                         }
2055
2056                         fr_hmac_md5(packet->data, packet->data_len,
2057                                     (const uint8_t *) secret, strlen(secret),
2058                                     calc_auth_vector);
2059                         if (digest_cmp(calc_auth_vector, msg_auth_vector,
2060                                    sizeof(calc_auth_vector)) != 0) {
2061                                 char buffer[32];
2062                                 fr_strerror_printf("Received packet from %s with invalid Message-Authenticator!  (Shared secret is incorrect.)",
2063                                            inet_ntop(packet->src_ipaddr.af,
2064                                                      &packet->src_ipaddr.ipaddr,
2065                                                      buffer, sizeof(buffer)));
2066                                 /* Silently drop packet, according to RFC 3579 */
2067                                 return -1;
2068                         } /* else the message authenticator was good */
2069
2070                         /*
2071                          *      Reinitialize Authenticators.
2072                          */
2073                         memcpy(&ptr[2], msg_auth_vector, AUTH_VECTOR_LEN);
2074                         memcpy(packet->data + 4, packet->vector, AUTH_VECTOR_LEN);
2075                         break;
2076                 } /* switch over the attributes */
2077
2078                 ptr += attrlen;
2079                 length -= attrlen;
2080         } /* loop over the packet, sanity checking the attributes */
2081
2082         /*
2083          *      It looks like a RADIUS packet, but we can't validate
2084          *      the signature.
2085          */
2086         if ((packet->code == 0) || (packet->code >= FR_MAX_PACKET_CODE)) {
2087                 char buffer[32];
2088                 fr_strerror_printf("Received Unknown packet code %d "
2089                            "from client %s port %d: Cannot validate signature.",
2090                            packet->code,
2091                            inet_ntop(packet->src_ipaddr.af,
2092                                      &packet->src_ipaddr.ipaddr,
2093                                      buffer, sizeof(buffer)),
2094                            packet->src_port);
2095                 return -1;
2096         }
2097
2098         /*
2099          *      Calculate and/or verify digest.
2100          */
2101         switch(packet->code) {
2102                 int rcode;
2103                 char buffer[32];
2104
2105                 case PW_AUTHENTICATION_REQUEST:
2106                 case PW_STATUS_SERVER:
2107                         /*
2108                          *      The authentication vector is random
2109                          *      nonsense, invented by the client.
2110                          */
2111                         break;
2112
2113                 case PW_COA_REQUEST:
2114                 case PW_DISCONNECT_REQUEST:
2115                 case PW_ACCOUNTING_REQUEST:
2116                         if (calc_acctdigest(packet, secret) > 1) {
2117                                 fr_strerror_printf("Received %s packet "
2118                                            "from %s with invalid signature!  (Shared secret is incorrect.)",
2119                                            fr_packet_codes[packet->code],
2120                                            inet_ntop(packet->src_ipaddr.af,
2121                                                      &packet->src_ipaddr.ipaddr,
2122                                                      buffer, sizeof(buffer)));
2123                                 return -1;
2124                         }
2125                         break;
2126
2127                         /* Verify the reply digest */
2128                 case PW_AUTHENTICATION_ACK:
2129                 case PW_AUTHENTICATION_REJECT:
2130                 case PW_ACCESS_CHALLENGE:
2131                 case PW_ACCOUNTING_RESPONSE:
2132                 case PW_DISCONNECT_ACK:
2133                 case PW_DISCONNECT_NAK:
2134                 case PW_COA_ACK:
2135                 case PW_COA_NAK:
2136                         rcode = calc_replydigest(packet, original, secret);
2137                         if (rcode > 1) {
2138                                 fr_strerror_printf("Received %s packet "
2139                                            "from client %s port %d with invalid signature (err=%d)!  (Shared secret is incorrect.)",
2140                                            fr_packet_codes[packet->code],
2141                                            inet_ntop(packet->src_ipaddr.af,
2142                                                      &packet->src_ipaddr.ipaddr,
2143                                                      buffer, sizeof(buffer)),
2144                                            packet->src_port,
2145                                            rcode);
2146                                 return -1;
2147                         }
2148                         break;
2149
2150                 default:
2151                         fr_strerror_printf("Received Unknown packet code %d "
2152                                    "from client %s port %d: Cannot validate signature",
2153                                    packet->code,
2154                                    inet_ntop(packet->src_ipaddr.af,
2155                                              &packet->src_ipaddr.ipaddr,
2156                                                      buffer, sizeof(buffer)),
2157                                    packet->src_port);
2158                         return -1;
2159         }
2160
2161         return 0;
2162 }
2163
2164
2165 static VALUE_PAIR *data2vp(const RADIUS_PACKET *packet,
2166                            const RADIUS_PACKET *original,
2167                            const char *secret, size_t length,
2168                            const uint8_t *data, VALUE_PAIR *vp)
2169 {
2170         int offset = 0;
2171
2172         /*
2173          *      If length is greater than 253, something is SERIOUSLY
2174          *      wrong.
2175          */
2176         if (length > 253) length = 253; /* paranoia (pair-anoia?) */
2177
2178         vp->length = length;
2179         vp->operator = T_OP_EQ;
2180         vp->next = NULL;
2181
2182         /*
2183          *      Handle tags.
2184          */
2185         if (vp->flags.has_tag) {
2186                 if (TAG_VALID(data[0]) ||
2187                     (vp->flags.encrypt == FLAG_ENCRYPT_TUNNEL_PASSWORD)) {
2188                         /*
2189                          *      Tunnel passwords REQUIRE a tag, even
2190                          *      if don't have a valid tag.
2191                          */
2192                         vp->flags.tag = data[0];
2193
2194                         if ((vp->type == PW_TYPE_STRING) ||
2195                             (vp->type == PW_TYPE_OCTETS)) {
2196                                 if (length == 0) goto raw;
2197                                 offset = 1;
2198                         }
2199                 }
2200         }
2201
2202         /*
2203          *      Copy the data to be decrypted
2204          */
2205         memcpy(&vp->vp_octets[0], data + offset, length - offset);
2206         vp->length -= offset;
2207
2208         /*
2209          *      Decrypt the attribute.
2210          */
2211         switch (vp->flags.encrypt) {
2212                 /*
2213                  *  User-Password
2214                  */
2215         case FLAG_ENCRYPT_USER_PASSWORD:
2216                 if (original) {
2217                         rad_pwdecode((char *)vp->vp_strvalue,
2218                                      vp->length, secret,
2219                                      original->vector);
2220                 } else {
2221                         rad_pwdecode((char *)vp->vp_strvalue,
2222                                      vp->length, secret,
2223                                      packet->vector);
2224                 }
2225                 if (vp->attribute == PW_USER_PASSWORD) {
2226                         vp->length = strlen(vp->vp_strvalue);
2227                 }
2228                 break;
2229
2230                 /*
2231                  *      Tunnel-Password's may go ONLY
2232                  *      in response packets.
2233                  */
2234         case FLAG_ENCRYPT_TUNNEL_PASSWORD:
2235                 if (!original) goto raw;
2236
2237                 if (rad_tunnel_pwdecode(vp->vp_octets, &vp->length,
2238                                         secret, original->vector) < 0) {
2239                         goto raw;
2240                 }
2241                 break;
2242
2243                 /*
2244                  *  Ascend-Send-Secret
2245                  *  Ascend-Receive-Secret
2246                  */
2247         case FLAG_ENCRYPT_ASCEND_SECRET:
2248                 if (!original) {
2249                         goto raw;
2250                 } else {
2251                         uint8_t my_digest[AUTH_VECTOR_LEN];
2252                         make_secret(my_digest,
2253                                     original->vector,
2254                                     secret, data);
2255                         memcpy(vp->vp_strvalue, my_digest,
2256                                AUTH_VECTOR_LEN );
2257                         vp->vp_strvalue[AUTH_VECTOR_LEN] = '\0';
2258                         vp->length = strlen(vp->vp_strvalue);
2259                 }
2260                 break;
2261
2262         default:
2263                 break;
2264         } /* switch over encryption flags */
2265
2266
2267         switch (vp->type) {
2268         case PW_TYPE_STRING:
2269         case PW_TYPE_OCTETS:
2270         case PW_TYPE_ABINARY:
2271                 /* nothing more to do */
2272                 break;
2273
2274         case PW_TYPE_BYTE:
2275                 if (vp->length != 1) goto raw;
2276
2277                 vp->vp_integer = vp->vp_octets[0];
2278                 break;
2279
2280
2281         case PW_TYPE_SHORT:
2282                 if (vp->length != 2) goto raw;
2283
2284                 vp->vp_integer = (vp->vp_octets[0] << 8) | vp->vp_octets[1];
2285                 break;
2286
2287         case PW_TYPE_INTEGER:
2288                 if (vp->length != 4) goto raw;
2289
2290                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2291                 vp->vp_integer = ntohl(vp->vp_integer);
2292
2293                 if (vp->flags.has_tag) vp->vp_integer &= 0x00ffffff;
2294
2295                 /*
2296                  *      Try to get named VALUEs
2297                  */
2298                 {
2299                         DICT_VALUE *dval;
2300                         dval = dict_valbyattr(vp->attribute, vp->vendor,
2301                                               vp->vp_integer);
2302                         if (dval) {
2303                                 strlcpy(vp->vp_strvalue,
2304                                         dval->name,
2305                                         sizeof(vp->vp_strvalue));
2306                         }
2307                 }
2308                 break;
2309
2310         case PW_TYPE_DATE:
2311                 if (vp->length != 4) goto raw;
2312
2313                 memcpy(&vp->vp_date, vp->vp_octets, 4);
2314                 vp->vp_date = ntohl(vp->vp_date);
2315                 break;
2316
2317
2318         case PW_TYPE_IPADDR:
2319                 if (vp->length != 4) goto raw;
2320
2321                 memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2322                 break;
2323
2324                 /*
2325                  *      IPv6 interface ID is 8 octets long.
2326                  */
2327         case PW_TYPE_IFID:
2328                 if (vp->length != 8) goto raw;
2329                 /* vp->vp_ifid == vp->vp_octets */
2330                 break;
2331
2332                 /*
2333                  *      IPv6 addresses are 16 octets long
2334                  */
2335         case PW_TYPE_IPV6ADDR:
2336                 if (vp->length != 16) goto raw;
2337                 /* vp->vp_ipv6addr == vp->vp_octets */
2338                 break;
2339
2340                 /*
2341                  *      IPv6 prefixes are 2 to 18 octets long.
2342                  *
2343                  *      RFC 3162: The first octet is unused.
2344                  *      The second is the length of the prefix
2345                  *      the rest are the prefix data.
2346                  *
2347                  *      The prefix length can have value 0 to 128.
2348                  */
2349         case PW_TYPE_IPV6PREFIX:
2350                 if (vp->length < 2 || vp->length > 18) goto raw;
2351                 if (vp->vp_octets[1] > 128) goto raw;
2352
2353                 /*
2354                  *      FIXME: double-check that
2355                  *      (vp->vp_octets[1] >> 3) matches vp->length + 2
2356                  */
2357                 if (vp->length < 18) {
2358                         memset(vp->vp_octets + vp->length, 0,
2359                                18 - vp->length);
2360                 }
2361                 break;
2362
2363         case PW_TYPE_SIGNED:
2364                 if (vp->length != 4) goto raw;
2365
2366                 /*
2367                  *      Overload vp_integer for ntohl, which takes
2368                  *      uint32_t, not int32_t
2369                  */
2370                 memcpy(&vp->vp_integer, vp->vp_octets, 4);
2371                 vp->vp_integer = ntohl(vp->vp_integer);
2372                 memcpy(&vp->vp_signed, &vp->vp_integer, 4);
2373                 break;
2374
2375         case PW_TYPE_TLV:
2376                 vp->length = length;
2377                 vp->vp_tlv = malloc(length);
2378                 if (!vp->vp_tlv) {
2379                         pairfree(&vp);
2380                         fr_strerror_printf("No memory");
2381                         return NULL;
2382                 }
2383                 memcpy(vp->vp_tlv, data, length);
2384                 break;
2385
2386         case PW_TYPE_COMBO_IP:
2387                 if (vp->length == 4) {
2388                         vp->type = PW_TYPE_IPADDR;
2389                         memcpy(&vp->vp_ipaddr, vp->vp_octets, 4);
2390                         break;
2391
2392                 } else if (vp->length == 16) {
2393                         vp->type = PW_TYPE_IPV6ADDR;
2394                         /* vp->vp_ipv6addr == vp->vp_octets */
2395                         break;
2396
2397                 }
2398                 /* FALL-THROUGH */
2399
2400         default:
2401         raw:
2402                 vp->type = PW_TYPE_OCTETS;
2403                 vp->length = length;
2404                 memcpy(vp->vp_octets, data, length);
2405
2406
2407                 /*
2408                  *      Ensure there's no encryption or tag stuff,
2409                  *      we just pass the attribute as-is.
2410                  */
2411                 memset(&vp->flags, 0, sizeof(vp->flags));
2412         }
2413
2414         return vp;
2415 }
2416
2417 static void rad_sortvp(VALUE_PAIR **head)
2418 {
2419         int swapped;
2420         VALUE_PAIR *vp, **tail;
2421
2422         /*
2423          *      Walk over the VP's, sorting them in order.  Did I
2424          *      mention that I hate WiMAX continuations?
2425          *
2426          *      And bubble sort!  WTF is up with that?
2427          */
2428         do {
2429                 swapped = 0;
2430                 tail = head;
2431                 while (*tail) {
2432                         vp = *tail;
2433                         if (!vp->next) break;
2434
2435                         if (vp->attribute > vp->next->attribute) {
2436                                 *tail = vp->next;
2437                                 vp->next = (*tail)->next;
2438                                 (*tail)->next = vp;
2439                                 swapped = 1;
2440                         }
2441                         tail = &(vp->next);
2442                 }
2443         } while (swapped);
2444 }
2445
2446
2447 /*
2448  *      Walk the packet, looking for continuations of this attribute.
2449  *
2450  *      This is (worst-case) O(N^2) in the number of RADIUS
2451  *      attributes.  That happens only when perverse clients create
2452  *      continued attributes, AND separate the fragmented portions
2453  *      with a lot of other attributes.
2454  *
2455  *      Sane clients should put the fragments next to each other, in
2456  *      which case this is O(N), in the number of fragments.
2457  */
2458 static uint8_t *rad_coalesce(unsigned int attribute, int vendor,
2459                              size_t length, uint8_t *data,
2460                              size_t packet_length, size_t *ptlv_length)
2461
2462 {
2463         uint32_t lvalue;
2464         size_t tlv_length = length;
2465         uint8_t *ptr, *tlv, *tlv_data;
2466
2467         for (ptr = data + length;
2468              ptr != (data + packet_length);
2469              ptr += ptr[1]) {
2470                 /* FIXME: Check that there are 6 bytes of data here... */
2471                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2472                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2473                     (ptr[2] != 0) || (ptr[3] != 0) ||  /* our requirement */
2474                     (ptr[4] != ((vendor >> 8) & 0xff)) ||
2475                     (ptr[5] != (vendor & 0xff))) {
2476                         continue;
2477                 }
2478
2479                 memcpy(&lvalue, ptr + 2, 4); /* Vendor Id */
2480                 lvalue = ntohl(lvalue);
2481                 lvalue <<= 16;
2482                 lvalue |= ptr[2 + 4]; /* add in VSA number */
2483                 if (lvalue != attribute) continue;
2484
2485                 /*
2486                  *      If the vendor-length is too small, it's badly
2487                  *      formed, so we stop.
2488                  */
2489                 if ((ptr[2 + 4 + 1]) < 3) break;
2490
2491                 tlv_length += ptr[2 + 4 + 1] - 3;
2492                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2493         }
2494
2495         tlv = tlv_data = malloc(tlv_length);
2496         if (!tlv_data) return NULL;
2497
2498         memcpy(tlv, data, length);
2499         tlv += length;
2500
2501         /*
2502          *      Now we walk the list again, copying the data over to
2503          *      our newly created memory.
2504          */
2505         for (ptr = data + length;
2506              ptr != (data + packet_length);
2507              ptr += ptr[1]) {
2508                 int this_length;
2509
2510                 if ((ptr[0] != PW_VENDOR_SPECIFIC) ||
2511                     (ptr[1] < (2 + 4 + 3)) || /* WiMAX VSA with continuation */
2512                     (ptr[2] != 0) || (ptr[3] != 0)) { /* our requirement */
2513                         continue;
2514                 }
2515
2516                 memcpy(&lvalue, ptr + 2, 4);
2517                 lvalue = ntohl(lvalue);
2518                 lvalue <<= 16;
2519                 lvalue |= ptr[2 + 4];
2520                 if (lvalue != attribute) continue;
2521
2522                 /*
2523                  *      If the vendor-length is too small, it's badly
2524                  *      formed, so we stop.
2525                  */
2526                 if ((ptr[2 + 4 + 1]) < 3) break;
2527
2528                 this_length = ptr[2 + 4 + 1] - 3;
2529                 memcpy(tlv, ptr + 2 + 4 + 3, this_length);
2530                 tlv += this_length;
2531
2532                 ptr[2 + 4] = 0; /* What a hack! */
2533                 if ((ptr[2 + 4 + 1 + 1] & 0x80) == 0) break;
2534         }
2535
2536         *ptlv_length = tlv_length;
2537         return tlv_data;
2538 }
2539
2540 extern int fr_wimax_shift[];
2541
2542
2543 /*
2544  *      Walk over Evil WIMAX TLVs, creating attributes.
2545  */
2546 static VALUE_PAIR *tlv2wimax(const RADIUS_PACKET *packet,
2547                              const RADIUS_PACKET *original,
2548                              const char *secret,
2549                              int attribute, int vendor,
2550                              uint8_t *ptr, size_t len, int nest)
2551 {
2552         VALUE_PAIR *head = NULL;
2553         VALUE_PAIR **tail = &head;
2554         VALUE_PAIR *vp;
2555         uint8_t *y;             /* why do I need to do this? */
2556
2557         if (nest > 4) return NULL;
2558
2559         /*
2560          *      Sanity check the attribute.
2561          */
2562         for (y = ptr; y < (ptr + len); y += y[1]) {
2563                 if ((y[0] == 0) || ((y + 2) > (ptr + len)) ||
2564                     (y[1] < 2) || ((y + y[1]) > (ptr + len))) {
2565                         return NULL;
2566                 }
2567         }
2568
2569         for (y = ptr; y < (ptr + len); y += y[1]) {
2570                 DICT_ATTR *da;
2571
2572                 da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor);
2573                 if (da && (da->type == PW_TYPE_TLV)) {
2574                         vp = tlv2wimax(packet, original, secret,
2575                                        attribute | (ptr[0] << fr_wimax_shift[nest]),
2576                                        vendor, ptr + 2, ptr[1] - 2,
2577                                        nest + 1);
2578                         if (!vp) goto error;
2579                 } else {
2580                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[nest]), vendor,
2581                                         PW_TYPE_OCTETS);
2582                         if (!vp) {
2583                         error:
2584                                 pairfree(&head);
2585                                 return NULL;
2586                         }
2587
2588                         if (!data2vp(packet, original, secret,
2589                                      y[1] - 2, y + 2, vp)) {
2590                                 goto error;
2591                         }
2592                 }
2593
2594                 *tail = vp;
2595                 while (*tail) tail = &((*tail)->next);
2596         }
2597
2598         return head;
2599 }
2600
2601 /*
2602  *      Start at the *data* portion of a continued attribute.  search
2603  *      through the rest of the attributes to find a matching one, and
2604  *      add it's contents to our contents.
2605  */
2606 static VALUE_PAIR *rad_continuation2vp(const RADIUS_PACKET *packet,
2607                                        const RADIUS_PACKET *original,
2608                                        const char *secret, int attribute,
2609                                        int vendor,
2610                                        int length, /* CANNOT be zero */
2611                                        uint8_t *data, size_t packet_length,
2612                                        int flag, DICT_ATTR *da)
2613 {
2614         size_t tlv_length, left;
2615         uint8_t *ptr;
2616         uint8_t *tlv_data;
2617         VALUE_PAIR *vp, *head, **tail;
2618         DICT_ATTR *tlv_da;
2619
2620         /*
2621          *      Ensure we have data that hasn't been split across
2622          *      multiple attributes.
2623          */
2624         if (flag) {
2625                 tlv_data = rad_coalesce(attribute, vendor, length,
2626                                         data, packet_length, &tlv_length);
2627                 if (!tlv_data) return NULL;
2628         } else {
2629                 tlv_data = data;
2630                 tlv_length = length;
2631         }
2632
2633         /*
2634          *      Non-TLV types cannot be continued across multiple
2635          *      attributes.  This is true even of keys that are
2636          *      encrypted with the tunnel-password method.  The spec
2637          *      says that they can be continued... but also that the
2638          *      keys are 160 bits, which means that they CANNOT be
2639          *      continued.  <sigh>
2640          *
2641          *      Note that we don't check "flag" here.  The calling
2642          *      code ensures that
2643          */
2644         if (!da || (da->type != PW_TYPE_TLV)) {
2645         not_well_formed:
2646                 if (tlv_data == data) { /* true if we had 'goto' */
2647                         tlv_data = malloc(tlv_length);
2648                         if (!tlv_data) return NULL;
2649                         memcpy(tlv_data, data, tlv_length);
2650                 }
2651
2652                 vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2653                 if (!vp) return NULL;
2654
2655                 vp->type = PW_TYPE_TLV;
2656                 vp->flags.encrypt = FLAG_ENCRYPT_NONE;
2657                 vp->flags.has_tag = 0;
2658                 vp->flags.is_tlv = 0;
2659                 vp->vp_tlv = tlv_data;
2660                 vp->length = tlv_length;
2661                 return vp;
2662         } /* else it WAS a TLV, go decode the sub-tlv's */
2663
2664         /*
2665          *      Now (sigh) we walk over the TLV, seeing if it is
2666          *      well-formed.
2667          */
2668         left = tlv_length;
2669         for (ptr = tlv_data;
2670              ptr != (tlv_data + tlv_length);
2671              ptr += ptr[1]) {
2672                 if ((left < 2) ||
2673                     (ptr[1] < 2) ||
2674                     (ptr[1] > left)) {
2675                         goto not_well_formed;
2676                 }
2677
2678                 left -= ptr[1];
2679         }
2680
2681         /*
2682          *      Now we walk over the TLV *again*, creating sub-tlv's.
2683          */
2684         head = NULL;
2685         tail = &head;
2686
2687         for (ptr = tlv_data;
2688              ptr != (tlv_data + tlv_length);
2689              ptr += ptr[1]) {
2690
2691                 tlv_da = dict_attrbyvalue(attribute | (ptr[0] << fr_wimax_shift[1]), vendor);
2692                 if (tlv_da && (tlv_da->type == PW_TYPE_TLV)) {
2693                         vp = tlv2wimax(packet, original, secret,
2694                                        attribute | (ptr[0] << 8),
2695                                        vendor, ptr + 2, ptr[1] - 2, 2);
2696
2697                         if (!vp) goto error;
2698                 } else {
2699                         vp = paircreate(attribute | (ptr[0] << fr_wimax_shift[1]), vendor,
2700                                         PW_TYPE_OCTETS);
2701                         if (!vp) {
2702                         error:
2703                                 pairfree(&head);
2704                                 goto not_well_formed;
2705                         }
2706
2707                         if (!data2vp(packet, original, secret,
2708                                      ptr[1] - 2, ptr + 2, vp)) {
2709                                 goto error;
2710                         }
2711                 }
2712
2713                 *tail = vp;
2714
2715                 while (*tail) tail = &((*tail)->next);
2716         }
2717
2718         /*
2719          *      TLV's MAY be continued, but sometimes they're not.
2720          */
2721         if (tlv_data != data) free(tlv_data);
2722
2723         if (head->next) rad_sortvp(&head);
2724
2725         return head;
2726 }
2727
2728
2729 /*
2730  *      Parse a RADIUS attribute into a data structure.
2731  */
2732 VALUE_PAIR *rad_attr2vp(const RADIUS_PACKET *packet,
2733                         const RADIUS_PACKET *original,
2734                         const char *secret, int attribute, int vendor,
2735                         int length, const uint8_t *data)
2736 {
2737         VALUE_PAIR *vp;
2738
2739         vp = paircreate(attribute, vendor, PW_TYPE_OCTETS);
2740         if (!vp) return NULL;
2741
2742         return data2vp(packet, original, secret, length, data, vp);
2743 }
2744
2745
2746 /*
2747  *      Calculate/check digest, and decode radius attributes.
2748  *      Returns:
2749  *      -1 on decoding error
2750  *      0 on success
2751  */
2752 int rad_decode(RADIUS_PACKET *packet, RADIUS_PACKET *original,
2753                const char *secret)
2754 {
2755         uint32_t                lvalue;
2756         uint32_t                vendorcode;
2757         VALUE_PAIR              **tail;
2758         VALUE_PAIR              *pair;
2759         uint8_t                 *ptr, *vsa_ptr;
2760         int                     packet_length;
2761         int                     attribute;
2762         int                     attrlen;
2763         int                     vendorlen;
2764         radius_packet_t         *hdr;
2765         int                     vsa_tlen, vsa_llen, vsa_offset;
2766         DICT_VENDOR             *dv = NULL;
2767         int                     num_attributes = 0;
2768
2769         /*
2770          *      Extract attribute-value pairs
2771          */
2772         hdr = (radius_packet_t *)packet->data;
2773         ptr = hdr->data;
2774         packet_length = packet->data_len - AUTH_HDR_LEN;
2775
2776         /*
2777          *      There may be VP's already in the packet.  Don't
2778          *      destroy them.
2779          */
2780         for (tail = &packet->vps; *tail != NULL; tail = &((*tail)->next)) {
2781                 /* nothing */
2782         }
2783
2784         vendorcode = 0;
2785         vendorlen  = 0;
2786         vsa_tlen = vsa_llen = 1;
2787         vsa_offset = 0;
2788
2789         /*
2790          *      We have to read at least two bytes.
2791          *
2792          *      rad_recv() above ensures that this is OK.
2793          */
2794         while (packet_length > 0) {
2795                 attribute = -1;
2796                 attrlen = -1;
2797
2798                 /*
2799                  *      Normal attribute, handle it like normal.
2800                  */
2801                 if (vendorcode == 0) {
2802                         /*
2803                          *      No room to read attr/length,
2804                          *      or bad attribute, or attribute is
2805                          *      too short, or attribute is too long,
2806                          *      stop processing the packet.
2807                          */
2808                         if ((packet_length < 2) ||
2809                             (ptr[0] == 0) ||  (ptr[1] < 2) ||
2810                             (ptr[1] > packet_length)) break;
2811
2812                         attribute = *ptr++;
2813                         attrlen   = *ptr++;
2814
2815                         attrlen -= 2;
2816                         packet_length  -= 2;
2817
2818                         if (attribute != PW_VENDOR_SPECIFIC) goto create_pair;
2819
2820                         /*
2821                          *      No vendor code, or ONLY vendor code.
2822                          */
2823                         if (attrlen <= 4) goto create_pair;
2824
2825                         vendorlen = 0;
2826                 }
2827
2828                 /*
2829                  *      Handle Vendor-Specific
2830                  */
2831                 if (vendorlen == 0) {
2832                         uint8_t *subptr;
2833                         int sublen;
2834                         int myvendor;
2835
2836                         /*
2837                          *      attrlen was checked above.
2838                          */
2839                         memcpy(&lvalue, ptr, 4);
2840                         myvendor = ntohl(lvalue);
2841
2842                         /*
2843                          *      Zero isn't allowed.
2844                          */
2845                         if (myvendor == 0) goto create_pair;
2846
2847                         /*
2848                          *      This is an implementation issue.
2849                          *      We currently pack vendor into the upper
2850                          *      16 bits of a 32-bit attribute number,
2851                          *      so we can't handle vendor numbers larger
2852                          *      than 16 bits.
2853                          */
2854                         if (myvendor > 65535) goto create_pair;
2855
2856                         vsa_tlen = vsa_llen = 1;
2857                         vsa_offset = 0;
2858                         dv = dict_vendorbyvalue(myvendor);
2859                         if (dv) {
2860                                 vsa_tlen = dv->type;
2861                                 vsa_llen = dv->length;
2862                                 if (dv->flags) vsa_offset = 1;
2863                         }
2864
2865                         /*
2866                          *      Sweep through the list of VSA's,
2867                          *      seeing if they exactly fill the
2868                          *      outer Vendor-Specific attribute.
2869                          *
2870                          *      If not, create a raw Vendor-Specific.
2871                          */
2872                         subptr = ptr + 4;
2873                         sublen = attrlen - 4;
2874
2875                         /*
2876                          *      See if we can parse it.
2877                          */
2878                         do {
2879                                 int myattr = 0;
2880
2881                                 /*
2882                                  *      Not enough room for one more
2883                                  *      attribute.  Die!
2884                                  */
2885                                 if (sublen < (vsa_tlen + vsa_llen + vsa_offset)) goto create_pair;
2886
2887                                 /*
2888                                  *      Ensure that the attribute number
2889                                  *      is OK.
2890                                  */
2891                                 switch (vsa_tlen) {
2892                                 case 1:
2893                                         myattr = subptr[0];
2894                                         break;
2895
2896                                 case 2:
2897                                         myattr = (subptr[0] << 8) | subptr[1];
2898                                         break;
2899
2900                                 case 4:
2901                                         if ((subptr[0] != 0) ||
2902                                             (subptr[1] != 0)) goto create_pair;
2903
2904                                         myattr = (subptr[2] << 8) | subptr[3];
2905                                         break;
2906
2907                                         /*
2908                                          *      Our dictionary is broken.
2909                                          */
2910                                 default:
2911                                         goto create_pair;
2912                                 }
2913
2914                                 switch (vsa_llen) {
2915                                 case 0:
2916                                         attribute = myattr;
2917                                         ptr += 4 + vsa_tlen;
2918                                         attrlen -= (4 + vsa_tlen);
2919                                         packet_length -= 4 + vsa_tlen;
2920                                         goto create_pair;
2921
2922                                 case 1:
2923                                         if (subptr[vsa_tlen] < (vsa_tlen + vsa_llen + vsa_offset))
2924                                                 goto create_pair;
2925
2926                                         if (subptr[vsa_tlen] > sublen)
2927                                                 goto create_pair;
2928
2929                                         /*
2930                                          *      WiMAX: 0bCrrrrrrr
2931                                          *      Reserved bits MUST be
2932                                          *      zero.
2933                                          */
2934                                         if (vsa_offset &&
2935                                             ((subptr[vsa_tlen + vsa_llen] & 0x7f) != 0))
2936                                                 goto create_pair;
2937
2938                                         sublen -= subptr[vsa_tlen];
2939                                         subptr += subptr[vsa_tlen];
2940                                         break;
2941
2942                                 case 2:
2943                                         if (subptr[vsa_tlen] != 0) goto create_pair;
2944                                         if (subptr[vsa_tlen + 1] < (vsa_tlen + vsa_llen))
2945                                                 goto create_pair;
2946                                         if (subptr[vsa_tlen + 1] > sublen)
2947                                                 goto create_pair;
2948                                         sublen -= subptr[vsa_tlen + 1];
2949                                         subptr += subptr[vsa_tlen + 1];
2950                                         break;
2951
2952                                         /*
2953                                          *      Our dictionaries are
2954                                          *      broken.
2955                                          */
2956                                 default:
2957                                         goto create_pair;
2958                                 }
2959                         } while (sublen > 0);
2960
2961                         vendorcode = myvendor;
2962                         vendorlen = attrlen - 4;
2963                         packet_length -= 4;
2964
2965                         ptr += 4;
2966                 }
2967
2968                 /*
2969                  *      attrlen is the length of this attribute.
2970                  *      total_len is the length of the encompassing
2971                  *      attribute.
2972                  */
2973                 switch (vsa_tlen) {
2974                 case 1:
2975                         attribute = ptr[0];
2976                         break;
2977
2978                 case 2:
2979                         attribute = (ptr[0] << 8) | ptr[1];
2980                         break;
2981
2982                 default:        /* can't hit this. */
2983                         return -1;
2984                 }
2985                 vsa_ptr = ptr;
2986                 ptr += vsa_tlen;
2987
2988                 switch (vsa_llen) {
2989                 case 1:
2990                         attrlen = ptr[0] - (vsa_tlen + vsa_llen + vsa_offset);
2991                         break;
2992
2993                 case 2:
2994                         attrlen = ptr[1] - (vsa_tlen + vsa_llen);
2995                         break;
2996
2997                 default:        /* can't hit this. */
2998                         return -1;
2999                 }
3000
3001                 ptr += vsa_llen + vsa_offset;
3002                 vendorlen -= vsa_tlen + vsa_llen + vsa_offset + attrlen;
3003                 packet_length -= (vsa_tlen + vsa_llen + vsa_offset);
3004
3005                 /*
3006                  *      Ignore VSAs that have no data.
3007                  */
3008                 if (attrlen == 0) goto next;
3009
3010                 /*
3011                  *      WiMAX attributes of type 0 are ignored.  They
3012                  *      are a secret flag to us that the attribute has
3013                  *      already been dealt with.
3014                  */
3015                 if ((vendorcode == VENDORPEC_WIMAX) && (attribute == 0)) {
3016                         goto next;
3017                 }
3018
3019                 if (vsa_offset) {
3020                         DICT_ATTR *da;
3021
3022                         da = dict_attrbyvalue(attribute, vendorcode);
3023
3024                         /*
3025                          *      If it's NOT continued, AND we know
3026                          *      about it, AND it's not a TLV, we can
3027                          *      create a normal pair.
3028                          */
3029                         if (((vsa_ptr[2] & 0x80) == 0) &&
3030                             da && (da->type != PW_TYPE_TLV)) goto create_pair;
3031
3032                         /*
3033                          *      Else it IS continued, or it's a TLV.
3034                          *      Go do a lot of work to find the stuff.
3035                          */
3036                         pair = rad_continuation2vp(packet, original, secret,
3037                                                    attribute, vendorcode,
3038                                                    attrlen, ptr,
3039                                                    packet_length,
3040                                                    ((vsa_ptr[2] & 0x80) != 0),
3041                                                    da);
3042                         goto created_pair;
3043                 }
3044
3045                 /*
3046                  *      Create the attribute, setting the default type
3047                  *      to 'octets'.  If the type in the dictionary
3048                  *      is different, then the dictionary type will
3049                  *      over-ride this one.
3050                  *
3051                  *      If the attribute has no data, then discard it.
3052                  *
3053                  *      Unless it's CUI.  Damn you, CUI!
3054                  */
3055         create_pair:
3056                 if (!attrlen &&
3057                     (attribute != PW_CHARGEABLE_USER_IDENTITY)) goto next;
3058
3059                 pair = rad_attr2vp(packet, original, secret,
3060                                    attribute, vendorcode, attrlen, ptr);
3061                 if (!pair) {
3062                         pairfree(&packet->vps);
3063                         fr_strerror_printf("out of memory");
3064                         return -1;
3065                 }
3066
3067         created_pair:
3068                 *tail = pair;
3069                 while (pair) {
3070                         num_attributes++;
3071                         debug_pair(pair);
3072                         tail = &pair->next;
3073                         pair = pair->next;
3074                 }
3075
3076                 /*
3077                  *      VSA's may not have been counted properly in
3078                  *      rad_packet_ok() above, as it is hard to count
3079                  *      then without using the dictionary.  We
3080                  *      therefore enforce the limits here, too.
3081                  */
3082                 if ((fr_max_attributes > 0) &&
3083                     (num_attributes > fr_max_attributes)) {
3084                         char host_ipaddr[128];
3085
3086                         pairfree(&packet->vps);
3087                         fr_strerror_printf("WARNING: Possible DoS attack from host %s: Too many attributes in request (received %d, max %d are allowed).",
3088                                    inet_ntop(packet->src_ipaddr.af,
3089                                              &packet->src_ipaddr.ipaddr,
3090                                              host_ipaddr, sizeof(host_ipaddr)),
3091                                    num_attributes, fr_max_attributes);
3092                         return -1;
3093                 }
3094
3095         next:
3096                 if (vendorlen == 0) vendorcode = 0;
3097                 ptr += attrlen;
3098                 packet_length -= attrlen;
3099         }
3100
3101         /*
3102          *      Merge information from the outside world into our
3103          *      random pool.
3104          */
3105         fr_rand_seed(packet->data, AUTH_HDR_LEN);
3106
3107         return 0;
3108 }
3109
3110
3111 /*
3112  *      Encode password.
3113  *
3114  *      We assume that the passwd buffer passed is big enough.
3115  *      RFC2138 says the password is max 128 chars, so the size
3116  *      of the passwd buffer must be at least 129 characters.
3117  *      Preferably it's just MAX_STRING_LEN.
3118  *
3119  *      int *pwlen is updated to the new length of the encrypted
3120  *      password - a multiple of 16 bytes.
3121  */
3122 int rad_pwencode(char *passwd, size_t *pwlen, const char *secret,
3123                  const uint8_t *vector)
3124 {
3125         FR_MD5_CTX context, old;
3126         uint8_t digest[AUTH_VECTOR_LEN];
3127         int     i, n, secretlen;
3128         int     len;
3129
3130         /*
3131          *      RFC maximum is 128 bytes.
3132          *
3133          *      If length is zero, pad it out with zeros.
3134          *
3135          *      If the length isn't aligned to 16 bytes,
3136          *      zero out the extra data.
3137          */
3138         len = *pwlen;
3139
3140         if (len > 128) len = 128;
3141
3142         if (len == 0) {
3143                 memset(passwd, 0, AUTH_PASS_LEN);
3144                 len = AUTH_PASS_LEN;
3145         } else if ((len % AUTH_PASS_LEN) != 0) {
3146                 memset(&passwd[len], 0, AUTH_PASS_LEN - (len % AUTH_PASS_LEN));
3147                 len += AUTH_PASS_LEN - (len % AUTH_PASS_LEN);
3148         }
3149         *pwlen = len;
3150
3151         /*
3152          *      Use the secret to setup the decryption digest
3153          */
3154         secretlen = strlen(secret);
3155
3156         fr_MD5Init(&context);
3157         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3158         old = context;          /* save intermediate work */
3159
3160         /*
3161          *      Encrypt it in place.  Don't bother checking
3162          *      len, as we've ensured above that it's OK.
3163          */
3164         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3165                 if (n == 0) {
3166                         fr_MD5Update(&context, vector, AUTH_PASS_LEN);
3167                         fr_MD5Final(digest, &context);
3168                 } else {
3169                         context = old;
3170                         fr_MD5Update(&context,
3171                                      (uint8_t *) passwd + n - AUTH_PASS_LEN,
3172                                      AUTH_PASS_LEN);
3173                         fr_MD5Final(digest, &context);
3174                 }
3175
3176                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3177                         passwd[i + n] ^= digest[i];
3178                 }
3179         }
3180
3181         return 0;
3182 }
3183
3184 /*
3185  *      Decode password.
3186  */
3187 int rad_pwdecode(char *passwd, size_t pwlen, const char *secret,
3188                  const uint8_t *vector)
3189 {
3190         FR_MD5_CTX context, old;
3191         uint8_t digest[AUTH_VECTOR_LEN];
3192         int     i;
3193         size_t  n, secretlen;
3194
3195         /*
3196          *      The RFC's say that the maximum is 128.
3197          *      The buffer we're putting it into above is 254, so
3198          *      we don't need to do any length checking.
3199          */
3200         if (pwlen > 128) pwlen = 128;
3201
3202         /*
3203          *      Catch idiots.
3204          */
3205         if (pwlen == 0) goto done;
3206
3207         /*
3208          *      Use the secret to setup the decryption digest
3209          */
3210         secretlen = strlen(secret);
3211
3212         fr_MD5Init(&context);
3213         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3214         old = context;          /* save intermediate work */
3215
3216         /*
3217          *      The inverse of the code above.
3218          */
3219         for (n = 0; n < pwlen; n += AUTH_PASS_LEN) {
3220                 if (n == 0) {
3221                         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3222                         fr_MD5Final(digest, &context);
3223
3224                         context = old;
3225                         if (pwlen > AUTH_PASS_LEN) {
3226                                 fr_MD5Update(&context, (uint8_t *) passwd,
3227                                              AUTH_PASS_LEN);
3228                         }
3229                 } else {
3230                         fr_MD5Final(digest, &context);
3231
3232                         context = old;
3233                         if (pwlen > (n + AUTH_PASS_LEN)) {
3234                                 fr_MD5Update(&context, (uint8_t *) passwd + n,
3235                                              AUTH_PASS_LEN);
3236                         }
3237                 }
3238
3239                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3240                         passwd[i + n] ^= digest[i];
3241                 }
3242         }
3243
3244  done:
3245         passwd[pwlen] = '\0';
3246         return strlen(passwd);
3247 }
3248
3249
3250 /*
3251  *      Encode Tunnel-Password attributes when sending them out on the wire.
3252  *
3253  *      int *pwlen is updated to the new length of the encrypted
3254  *      password - a multiple of 16 bytes.
3255  *
3256  *      This is per RFC-2868 which adds a two char SALT to the initial intermediate
3257  *      value MD5 hash.
3258  */
3259 int rad_tunnel_pwencode(char *passwd, size_t *pwlen, const char *secret,
3260                         const uint8_t *vector)
3261 {
3262         uint8_t buffer[AUTH_VECTOR_LEN + MAX_STRING_LEN + 3];
3263         unsigned char   digest[AUTH_VECTOR_LEN];
3264         char*   salt;
3265         int     i, n, secretlen;
3266         unsigned len, n2;
3267
3268         len = *pwlen;
3269
3270         if (len > 127) len = 127;
3271
3272         /*
3273          * Shift the password 3 positions right to place a salt and original
3274          * length, tag will be added automatically on packet send
3275          */
3276         for (n=len ; n>=0 ; n--) passwd[n+3] = passwd[n];
3277         salt = passwd;
3278         passwd += 2;
3279         /*
3280          * save original password length as first password character;
3281          */
3282         *passwd = len;
3283         len += 1;
3284
3285
3286         /*
3287          *      Generate salt.  The RFC's say:
3288          *
3289          *      The high bit of salt[0] must be set, each salt in a
3290          *      packet should be unique, and they should be random
3291          *
3292          *      So, we set the high bit, add in a counter, and then
3293          *      add in some CSPRNG data.  should be OK..
3294          */
3295         salt[0] = (0x80 | ( ((salt_offset++) & 0x0f) << 3) |
3296                    (fr_rand() & 0x07));
3297         salt[1] = fr_rand();
3298
3299         /*
3300          *      Padd password to multiple of AUTH_PASS_LEN bytes.
3301          */
3302         n = len % AUTH_PASS_LEN;
3303         if (n) {
3304                 n = AUTH_PASS_LEN - n;
3305                 for (; n > 0; n--, len++)
3306                         passwd[len] = 0;
3307         }
3308         /* set new password length */
3309         *pwlen = len + 2;
3310
3311         /*
3312          *      Use the secret to setup the decryption digest
3313          */
3314         secretlen = strlen(secret);
3315         memcpy(buffer, secret, secretlen);
3316
3317         for (n2 = 0; n2 < len; n2+=AUTH_PASS_LEN) {
3318                 if (!n2) {
3319                         memcpy(buffer + secretlen, vector, AUTH_VECTOR_LEN);
3320                         memcpy(buffer + secretlen + AUTH_VECTOR_LEN, salt, 2);
3321                         fr_md5_calc(digest, buffer, secretlen + AUTH_VECTOR_LEN + 2);
3322                 } else {
3323                         memcpy(buffer + secretlen, passwd + n2 - AUTH_PASS_LEN, AUTH_PASS_LEN);
3324                         fr_md5_calc(digest, buffer, secretlen + AUTH_PASS_LEN);
3325                 }
3326
3327                 for (i = 0; i < AUTH_PASS_LEN; i++) {
3328                         passwd[i + n2] ^= digest[i];
3329                 }
3330         }
3331         passwd[n2] = 0;
3332         return 0;
3333 }
3334
3335 /*
3336  *      Decode Tunnel-Password encrypted attributes.
3337  *
3338  *      Defined in RFC-2868, this uses a two char SALT along with the
3339  *      initial intermediate value, to differentiate it from the
3340  *      above.
3341  */
3342 int rad_tunnel_pwdecode(uint8_t *passwd, size_t *pwlen, const char *secret,
3343                         const uint8_t *vector)
3344 {
3345         FR_MD5_CTX  context, old;
3346         uint8_t         digest[AUTH_VECTOR_LEN];
3347         int             secretlen;
3348         unsigned        i, n, len, reallen;
3349
3350         len = *pwlen;
3351
3352         /*
3353          *      We need at least a salt.
3354          */
3355         if (len < 2) {
3356                 fr_strerror_printf("tunnel password is too short");
3357                 return -1;
3358         }
3359
3360         /*
3361          *      There's a salt, but no password.  Or, there's a salt
3362          *      and a 'data_len' octet.  It's wrong, but at least we
3363          *      can figure out what it means: the password is empty.
3364          *
3365          *      Note that this means we ignore the 'data_len' field,
3366          *      if the attribute length tells us that there's no
3367          *      more data.  So the 'data_len' field may be wrong,
3368          *      but that's ok...
3369          */
3370         if (len <= 3) {
3371                 passwd[0] = 0;
3372                 *pwlen = 0;
3373                 return 0;
3374         }
3375
3376         len -= 2;               /* discount the salt */
3377
3378         /*
3379          *      Use the secret to setup the decryption digest
3380          */
3381         secretlen = strlen(secret);
3382
3383         fr_MD5Init(&context);
3384         fr_MD5Update(&context, (const uint8_t *) secret, secretlen);
3385         old = context;          /* save intermediate work */
3386
3387         /*
3388          *      Set up the initial key:
3389          *
3390          *       b(1) = MD5(secret + vector + salt)
3391          */
3392         fr_MD5Update(&context, vector, AUTH_VECTOR_LEN);
3393         fr_MD5Update(&context, passwd, 2);
3394
3395         reallen = 0;
3396         for (n = 0; n < len; n += AUTH_PASS_LEN) {
3397                 int base = 0;
3398
3399                 if (n == 0) {
3400                         fr_MD5Final(digest, &context);
3401
3402                         context = old;
3403
3404                         /*
3405                          *      A quick check: decrypt the first octet
3406                          *      of the password, which is the
3407                          *      'data_len' field.  Ensure it's sane.
3408                          */
3409                         reallen = passwd[2] ^ digest[0];
3410                         if (reallen >= len) {
3411                                 fr_strerror_printf("tunnel password is too long for the attribute");
3412                                 return -1;
3413                         }
3414
3415                         fr_MD5Update(&context, passwd + 2, AUTH_PASS_LEN);
3416
3417                         base = 1;
3418                 } else {
3419                         fr_MD5Final(digest, &context);
3420
3421                         context = old;
3422                         fr_MD5Update(&context, passwd + n + 2, AUTH_PASS_LEN);
3423                 }
3424
3425                 for (i = base; i < AUTH_PASS_LEN; i++) {
3426                         passwd[n + i - 1] = passwd[n + i + 2] ^ digest[i];
3427                 }
3428         }
3429
3430         /*
3431          *      See make_tunnel_password, above.
3432          */
3433         if (reallen > 239) reallen = 239;
3434
3435         *pwlen = reallen;
3436         passwd[reallen] = 0;
3437
3438         return reallen;
3439 }
3440
3441 /*
3442  *      Encode a CHAP password
3443  *
3444  *      FIXME: might not work with Ascend because
3445  *      we use vp->length, and Ascend gear likes
3446  *      to send an extra '\0' in the string!
3447  */
3448 int rad_chap_encode(RADIUS_PACKET *packet, uint8_t *output, int id,
3449                     VALUE_PAIR *password)
3450 {
3451         int             i;
3452         uint8_t         *ptr;
3453         uint8_t         string[MAX_STRING_LEN * 2 + 1];
3454         VALUE_PAIR      *challenge;
3455
3456         /*
3457          *      Sanity check the input parameters
3458          */
3459         if ((packet == NULL) || (password == NULL)) {
3460                 return -1;
3461         }
3462
3463         /*
3464          *      Note that the password VP can be EITHER
3465          *      a User-Password attribute (from a check-item list),
3466          *      or a CHAP-Password attribute (the client asking
3467          *      the library to encode it).
3468          */
3469
3470         i = 0;
3471         ptr = string;
3472         *ptr++ = id;
3473
3474         i++;
3475         memcpy(ptr, password->vp_strvalue, password->length);
3476         ptr += password->length;
3477         i += password->length;
3478
3479         /*
3480          *      Use Chap-Challenge pair if present,
3481          *      Request-Authenticator otherwise.
3482          */
3483         challenge = pairfind(packet->vps, PW_CHAP_CHALLENGE, 0);
3484         if (challenge) {
3485                 memcpy(ptr, challenge->vp_strvalue, challenge->length);
3486                 i += challenge->length;
3487         } else {
3488                 memcpy(ptr, packet->vector, AUTH_VECTOR_LEN);
3489                 i += AUTH_VECTOR_LEN;
3490         }
3491
3492         *output = id;
3493         fr_md5_calc((uint8_t *)output + 1, (uint8_t *)string, i);
3494
3495         return 0;
3496 }
3497
3498
3499 /*
3500  *      Seed the random number generator.
3501  *
3502  *      May be called any number of times.
3503  */
3504 void fr_rand_seed(const void *data, size_t size)
3505 {
3506         uint32_t hash;
3507
3508         /*
3509          *      Ensure that the pool is initialized.
3510          */
3511         if (!fr_rand_initialized) {
3512                 int fd;
3513
3514                 memset(&fr_rand_pool, 0, sizeof(fr_rand_pool));
3515
3516                 fd = open("/dev/urandom", O_RDONLY);
3517                 if (fd >= 0) {
3518                         size_t total;
3519                         ssize_t this;
3520
3521                         total = this = 0;
3522                         while (total < sizeof(fr_rand_pool.randrsl)) {
3523                                 this = read(fd, fr_rand_pool.randrsl,
3524                                             sizeof(fr_rand_pool.randrsl) - total);
3525                                 if ((this < 0) && (errno != EINTR)) break;
3526                                 if (this > 0) total += this;
3527                         }
3528                         close(fd);
3529                 } else {
3530                         fr_rand_pool.randrsl[0] = fd;
3531                         fr_rand_pool.randrsl[1] = time(NULL);
3532                         fr_rand_pool.randrsl[2] = errno;
3533                 }
3534
3535                 fr_randinit(&fr_rand_pool, 1);
3536                 fr_rand_pool.randcnt = 0;
3537                 fr_rand_initialized = 1;
3538         }
3539
3540         if (!data) return;
3541
3542         /*
3543          *      Hash the user data
3544          */
3545         hash = fr_rand();
3546         if (!hash) hash = fr_rand();
3547         hash = fr_hash_update(data, size, hash);
3548
3549         fr_rand_pool.randmem[fr_rand_pool.randcnt] ^= hash;
3550 }
3551
3552
3553 /*
3554  *      Return a 32-bit random number.
3555  */
3556 uint32_t fr_rand(void)
3557 {
3558         uint32_t num;
3559
3560         /*
3561          *      Ensure that the pool is initialized.
3562          */
3563         if (!fr_rand_initialized) {
3564                 fr_rand_seed(NULL, 0);
3565         }
3566
3567         num = fr_rand_pool.randrsl[fr_rand_pool.randcnt++];
3568         if (fr_rand_pool.randcnt >= 256) {
3569                 fr_rand_pool.randcnt = 0;
3570                 fr_isaac(&fr_rand_pool);
3571         }
3572
3573         return num;
3574 }
3575
3576
3577 /*
3578  *      Allocate a new RADIUS_PACKET
3579  */
3580 RADIUS_PACKET *rad_alloc(int newvector)
3581 {
3582         RADIUS_PACKET   *rp;
3583
3584         if ((rp = malloc(sizeof(RADIUS_PACKET))) == NULL) {
3585                 fr_strerror_printf("out of memory");
3586                 return NULL;
3587         }
3588         memset(rp, 0, sizeof(*rp));
3589         rp->id = -1;
3590         rp->offset = -1;
3591
3592         if (newvector) {
3593                 int i;
3594                 uint32_t hash, base;
3595
3596                 /*
3597                  *      Don't expose the actual contents of the random
3598                  *      pool.
3599                  */
3600                 base = fr_rand();
3601                 for (i = 0; i < AUTH_VECTOR_LEN; i += sizeof(uint32_t)) {
3602                         hash = fr_rand() ^ base;
3603                         memcpy(rp->vector + i, &hash, sizeof(hash));
3604                 }
3605         }
3606         fr_rand();              /* stir the pool again */
3607
3608         return rp;
3609 }
3610
3611 RADIUS_PACKET *rad_alloc_reply(RADIUS_PACKET *packet)
3612 {
3613         RADIUS_PACKET *reply;
3614
3615         if (!packet) return NULL;
3616
3617         reply = rad_alloc(0);
3618         if (!reply) return NULL;
3619
3620         /*
3621          *      Initialize the fields from the request.
3622          */
3623         reply->sockfd = packet->sockfd;
3624         reply->dst_ipaddr = packet->src_ipaddr;
3625         reply->src_ipaddr = packet->dst_ipaddr;
3626         reply->dst_port = packet->src_port;
3627         reply->src_port = packet->dst_port;
3628         reply->id = packet->id;
3629         reply->code = 0; /* UNKNOWN code */
3630         memcpy(reply->vector, packet->vector,
3631                sizeof(reply->vector));
3632         reply->vps = NULL;
3633         reply->data = NULL;
3634         reply->data_len = 0;
3635
3636         return reply;
3637 }
3638
3639
3640 /*
3641  *      Free a RADIUS_PACKET
3642  */
3643 void rad_free(RADIUS_PACKET **radius_packet_ptr)
3644 {
3645         RADIUS_PACKET *radius_packet;
3646
3647         if (!radius_packet_ptr || !*radius_packet_ptr) return;
3648         radius_packet = *radius_packet_ptr;
3649
3650         free(radius_packet->data);
3651
3652         pairfree(&radius_packet->vps);
3653
3654         free(radius_packet);
3655
3656         *radius_packet_ptr = NULL;
3657 }